phantom alert sound

I am getting a ding/dong alert sound (very full with reverb/echo) at random moments while I am online.
I have checked everywhere I know for sounds, and Sound window doesn't have that sound in the list. I have set email at Comcast and on Live Mail to not notify me of incoming messages. The sound persists, occuring between 2-3 a minute to several in the course of an hour.
How can I find out what program or event is sending this alert? The only program running at all times (beside Security Essentials) is BackBlaze, backing up files as they are changed. An attempt to cause the sound by creating and deleting files didn't do anything.
This is starting to drive me nuts.

Thank you for the prompt reply.
I ran HijackThis, but it wouldn't give me anything more than a file with some comments. It said it couldn't write to hosts and gave me some information about manually setting up a 'hosts.' file. I haven't done that.
But you reminded me of Malwarebytes. For that I thank you. I got it and ran it. A bunch of entries from a games site which I had tried came up. I let Malwarebytes fix them, and then I removed a couple of other programs that I had at that point. I restored my registry from last week (I use Uniblue).
I heard the sound when I rebooted and loaded programs. At that point I removed a video viewer program (FLV-player) and rebooted.
I haven't heard the sound since.
I am suspecting it was the games site, but it's hard to tell.
I reviewed the event viewer logs (and cleaned them up while I was there) but didn't see anything in the timeframe when I heard the sound last night.
It might be gone, and I'm not about to reinstall the questionable programs to see if I can get it back.
But Malwarebytes really helped. And you! Thanks again.

Well, let's not be so hasty. Malwarebytes said it deleted two newly found malware programs, and the phantom chimes were back! I let Malwarebytes run again and it found the same two register entries again. I have deleted them again. Uniblue found them and a bunch of broken references to files associated with them and I cleared them from there as well.
Last report: the chimes are back. This is very annoying because as I sit here doing paperwork with no programs running, the computer chimes every now and then. Something is running. The only time I can predict it will happen is when I boot up - some program or other is starting and DING-DONG, there it is.
I looked at the starting services, but there are a lot of them, and some I am not familiar with so I don't want to start shutting them down willy nilly. Meanwhile, I finally set up HijackThis and got a report. It is below.
Anybody with insight will be appreciated. And so will the insight!

Logfile of Trend Micro HijackThis v2.0.4
Scan saved at 11:06:16 PM, on 4/19/2012
Platform: Windows 7 SP1 (WinNT 6.00.3505)
MSIE: Internet Explorer v9.00 (9.00.8112.16421)
Boot mode: Normal
Running processes:
C:\Program Files (x86)\Uniblue\RegistryBooster\rbmonitor.exe
C:\Program Files (x86)\Hewlett-Packard\HP Odometer\hpsysdrv.exe
C:\Program Files (x86)\Backblaze\bzbui.exe
C:\Program Files (x86)\Siber Systems\AI RoboForm\robotaskbaricon.exe
C:\Program Files (x86)\NETGEAR\WNA1100\WNA1100.exe
C:\Program Files (x86)\Hp\HP Software Update\hpwuschd2.exe
C:\Program Files (x86)\Microsoft Office\Office14\ONENOTEM.EXE
C:\Program Files (x86)\Canon\Canon IJ Network Scan Utility\CNMNSUT.exe
C:\Program Files (x86)\Real\RealPlayer\Update\realsched.exe
C:\Program Files (x86)\LeapFrog\LeapFrog Connect\Monitor.exe
C:\Program Files (x86)\Common Files\Java\Java Update\jusched.exe
C:\Program Files (x86)\Uniblue\RegistryBooster\RegistryBooster.exe
C:\Windows\SysWOW64\Macromed\Flash\FlashUtil32_11_2_202_233_ActiveX.exe
C:\Program Files (x86)\Windows Live\Mail\wlmail.exe
C:\Program Files (x86)\Windows Live\Contacts\wlcomm.exe
C:\Program Files (x86)\Internet Explorer\iexplore.exe
C:\Program Files (x86)\Internet Explorer\iexplore.exe
C:\Program Files (x86)\Trend Micro\HiJackThis\HiJackThis.exe
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = HP MSN.com
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = Bing
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = HP MSN.com
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = HP MSN.com
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = Bing
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = Bing
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = HP MSN.com
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant =
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,CustomizeSearch =
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Local Page =
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Local Page = C:\Windows\SysWOW64\blank.htm
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName =
R3 - URLSearchHook: (no name) - {2d7432c9-a3fd-4ed1-aea9-fbdb12dba4a7} - (no file)
F2 - REG:system.ini: UserInit=userinit.exe,
O2 - BHO: AcroIEHelperStub - {18DF081C-E8AD-4283-A596-FA578C2EBDC3} - C:\Program Files (x86)\Common Files\Adobe\Acrobat\ActiveX\AcroIEHelperShim.dll
O2 - BHO: RealPlayer Download and Record Plugin for Internet Explorer - {3049C3E9-B461-4BC5-8870-4C09146192CA} - C:\ProgramData\Real\RealPlayer\BrowserRecordPlugin\IE\rpbrowserrecordplugin.dll
O2 - BHO: RoboForm BHO - {724d43a9-0d85-11d4-9908-00400523e39a} - C:\Program Files (x86)\Siber Systems\AI RoboForm\roboform.dll
O2 - BHO: Java(tm) Plug-In SSV Helper - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files (x86)\Java\jre6\bin\ssv.dll
O2 - BHO: Windows Live ID Sign-in Helper - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Program Files (x86)\Common Files\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O2 - BHO: URLRedirectionBHO - {B4F3A835-0E21-4959-BA22-42B3008E02FF} - C:\PROGRA~2\MICROS~1\Office14\URLREDIR.DLL
O2 - BHO: Java(tm) Plug-In 2 SSV Helper - {DBC80044-A445-435b-BC74-9C25C1C588A9} - C:\Program Files (x86)\Java\jre6\bin\jp2ssv.dll
O3 - Toolbar: &RoboForm Toolbar - {724d43a0-0d85-11d4-9908-00400523e39a} - C:\Program Files (x86)\Siber Systems\AI RoboForm\roboform.dll
O4 - HKLM\..\Run: [HP Software Update] c:\Program Files (x86)\HP\HP Software Update\HPWuSchd2.exe
O4 - HKLM\..\Run: [PDF Complete] C:\Program Files (x86)\PDF Complete\pdfsty.exe
O4 - HKLM\..\Run: [jswtrayutil] "C:\Program Files (x86)\NETGEAR\WNA1100\jswtrayutil.exe"
O4 - HKLM\..\Run: [Adobe ARM] "C:\Program Files (x86)\Common Files\Adobe\ARM\1.0\AdobeARM.exe"
O4 - HKLM\..\Run: [IJNetworkScanUtility] C:\Program Files (x86)\Canon\Canon IJ Network Scan Utility\CNMNSUT.exe
O4 - HKLM\..\Run: [TkBellExe] "c:\program files (x86)\real\realplayer\Update\realsched.exe" -osboot
O4 - HKLM\..\Run: [Monitor] "C:\Program Files (x86)\LeapFrog\LeapFrog Connect\Monitor.exe"
O4 - HKLM\..\Run: [SunJavaUpdateSched] "C:\Program Files (x86)\Common Files\Java\Java Update\jusched.exe"
O4 - HKCU\..\Run: [Backblaze] "C:\Program Files (x86)\Backblaze\bzbui.exe" -quiet
O4 - HKCU\..\Run: [RoboForm] "C:\Program Files (x86)\Siber Systems\AI RoboForm\RoboTaskBarIcon.exe"
O4 - HKUS\S-1-5-19\..\Run: [Sidebar] %ProgramFiles%\Windows Sidebar\Sidebar.exe /autoRun (User 'LOCAL SERVICE')
O4 - HKUS\S-1-5-19\..\RunOnce: [mctadmin] C:\Windows\System32\mctadmin.exe (User 'LOCAL SERVICE')
O4 - HKUS\S-1-5-20\..\Run: [Sidebar] %ProgramFiles%\Windows Sidebar\Sidebar.exe /autoRun (User 'NETWORK SERVICE')
O4 - HKUS\S-1-5-20\..\RunOnce: [mctadmin] C:\Windows\System32\mctadmin.exe (User 'NETWORK SERVICE')
O4 - HKUS\S-1-5-18\..\Run: [Backblaze] "C:\Program Files (x86)\Backblaze\bzbui.exe" -quiet (User 'SYSTEM')
O4 - HKUS\.DEFAULT\..\Run: [Backblaze] "C:\Program Files (x86)\Backblaze\bzbui.exe" -quiet (User 'Default user')
O4 - Startup: OneNote 2010 Screen Clipper and Launcher.lnk = C:\Program Files (x86)\Microsoft Office\Office14\ONENOTEM.EXE
O4 - Global Startup: NETGEAR WNA1100 Smart Wizard.lnk = ?
O8 - Extra context menu item: Customize Menu - file://C:\Program Files (x86)\Siber Systems\AI RoboForm\RoboFormComCustomizeIEMenu.html
O8 - Extra context menu item: E&xport to Microsoft Excel - res://C:\PROGRA~2\MICROS~1\Office12\EXCEL.EXE/3000
O8 - Extra context menu item: Fill Forms - file://C:\Program Files (x86)\Siber Systems\AI RoboForm\RoboFormComFillForms.html
O8 - Extra context menu item: Password Generator - file://C:\Program Files (x86)\Siber Systems\AI RoboForm\RoboFormComPasswordGenerator.html
O8 - Extra context menu item: Save Forms - file://C:\Program Files (x86)\Siber Systems\AI RoboForm\RoboFormComSavePass.html
O8 - Extra context menu item: Se&nd to OneNote - res://C:\PROGRA~2\MICROS~1\Office14\ONBttnIE.dll/105
O8 - Extra context menu item: Show RoboForm Toolbar - file://C:\Program Files (x86)\Siber Systems\AI RoboForm\RoboFormComShowToolbar.html
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files (x86)\Java\jre6\bin\ssv.dll
O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files (x86)\Java\jre6\bin\ssv.dll
O9 - Extra button: @C:\Program Files (x86)\Windows Live\Writer\WindowsLiveWriterShortcuts.dll,-1004 - {219C3416-8CB2-491a-A3C7-D9FCDDC9D600} - C:\Program Files (x86)\Windows Live\Writer\WriterBrowserExtension.dll
O9 - Extra 'Tools' menuitem: @C:\Program Files (x86)\Windows Live\Writer\WindowsLiveWriterShortcuts.dll,-1003 - {219C3416-8CB2-491a-A3C7-D9FCDDC9D600} - C:\Program Files (x86)\Windows Live\Writer\WriterBrowserExtension.dll
O9 - Extra button: Send to OneNote - {2670000A-7350-4f3c-8081-5663EE0C6C49} - C:\Program Files (x86)\Microsoft Office\Office14\ONBttnIE.dll
O9 - Extra 'Tools' menuitem: Se&nd to OneNote - {2670000A-7350-4f3c-8081-5663EE0C6C49} - C:\Program Files (x86)\Microsoft Office\Office14\ONBttnIE.dll
O9 - Extra button: Show Toolbar - {724d43aa-0d85-11d4-9908-00400523e39a} - C:\Program Files (x86)\Siber Systems\AI RoboForm\roboform.dll
O9 - Extra 'Tools' menuitem: Show RoboForm Toolbar - {724d43aa-0d85-11d4-9908-00400523e39a} - C:\Program Files (x86)\Siber Systems\AI RoboForm\roboform.dll
O9 - Extra button: OneNote Lin&ked Notes - {789FE86F-6FC4-46A1-9849-EDE0DB0C95CA} - C:\Program Files (x86)\Microsoft Office\Office14\ONBttnIELinkedNotes.dll
O9 - Extra 'Tools' menuitem: OneNote Lin&ked Notes - {789FE86F-6FC4-46A1-9849-EDE0DB0C95CA} - C:\Program Files (x86)\Microsoft Office\Office14\ONBttnIELinkedNotes.dll
O9 - Extra button: Research - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~2\MICROS~1\Office12\REFIEBAR.DLL
O10 - Unknown file in Winsock LSP: c:\program files (x86)\common files\microsoft shared\windows live\wlidnsp.dll
O10 - Unknown file in Winsock LSP: c:\program files (x86)\common files\microsoft shared\windows live\wlidnsp.dll
O11 - Options group: [ACCELERATED_GRAPHICS] Accelerated graphics
O18 - Protocol: skype4com - {FFC8B962-9B40-4DFF-9458-1830C7DD7F5D} - C:\PROGRA~2\COMMON~1\Skype\SKYPE4~1.DLL
O18 - Protocol: wlpg - {E43EF6CD-A37A-4A9B-9E6F-83F89B8E6324} - C:\Program Files (x86)\Windows Live\Photo Gallery\AlbumDownloadProtocolHandler.dll
O23 - Service: Adobe Acrobat Update Service (AdobeARMservice) - Adobe Systems Incorporated - C:\Program Files (x86)\Common Files\Adobe\ARM\1.0\armsvc.exe
O23 - Service: Adobe Flash Player Update Service (AdobeFlashPlayerUpdateSvc) - Adobe Systems Incorporated - C:\Windows\SysWOW64\Macromed\Flash\FlashPlayerUpdateService.exe
O23 - Service: @%SystemRoot%\system32\Alg.exe,-112 (ALG) - Unknown owner - C:\Windows\System32\alg.exe (file missing)
O23 - Service: Backblaze Service (bzserv) - Unknown owner - C:\Program Files (x86)\Backblaze\bzserv.exe
O23 - Service: @%SystemRoot%\system32\efssvc.dll,-100 (EFS) - Unknown owner - C:\Windows\System32\lsass.exe (file missing)
O23 - Service: @%systemroot%\system32\fxsresm.dll,-118 (Fax) - Unknown owner - C:\Windows\system32\fxssvc.exe (file missing)
O23 - Service: HP Support Assistant Service - Hewlett-Packard Company - C:\Program Files (x86)\Hewlett-Packard\HP Support Framework\hpsa_service.exe
O23 - Service: HP Auto (HPAuto) - Hewlett-Packard - C:\Program Files\Hewlett-Packard\HP Auto\HPAuto.exe
O23 - Service: HP Client Services (HPClientSvc) - Hewlett-Packard Company - C:\Program Files\Hewlett-Packard\HP Client Services\HPClientServices.exe
O23 - Service: HP Quick Synchronization Service (HPDrvMntSvc.exe) - Hewlett-Packard Company - C:\Program Files (x86)\Hewlett-Packard\Shared\HPDrvMntSvc.exe
O23 - Service: HP Software Framework Service (hpqwmiex) - Hewlett-Packard Company - C:\Program Files (x86)\Hewlett-Packard\Shared\hpqWmiEx.exe
O23 - Service: Canon Inkjet Printer/Scanner/Fax Extended Survey Program (IJPLMSVC) - Unknown owner - C:\Program Files (x86)\Canon\IJPLM\IJPLMSVC.EXE
O23 - Service: JumpStart Wi-Fi Protected Setup (jswpsapi) - Atheros Communications, Inc. - C:\Program Files (x86)\NETGEAR\WNA1100\jswpsapi.exe
O23 - Service: @keyiso.dll,-100 (KeyIso) - Unknown owner - C:\Windows\system32\lsass.exe (file missing)
O23 - Service: LeapFrog Connect Device Service - LeapFrog Enterprises, Inc. - C:\Program Files (x86)\LeapFrog\LeapFrog Connect\CommandService.exe
O23 - Service: LightScribeService Direct Disc Labeling Service (LightScribeService) - Hewlett-Packard Company - c:\Program Files (x86)\Common Files\LightScribe\LSSrvc.exe
O23 - Service: @comres.dll,-2797 (MSDTC) - Unknown owner - C:\Windows\System32\msdtc.exe (file missing)
O23 - Service: @%SystemRoot%\System32\netlogon.dll,-102 (Netlogon) - Unknown owner - C:\Windows\system32\lsass.exe (file missing)
O23 - Service: PDF Document Manager (pdfcDispatcher) - PDF Complete Inc - C:\Program Files (x86)\PDF Complete\pdfsvc.exe
O23 - Service: @%systemroot%\system32\psbase.dll,-300 (ProtectedStorage) - Unknown owner - C:\Windows\system32\lsass.exe (file missing)
O23 - Service: @%systemroot%\system32\Locator.exe,-2 (RpcLocator) - Unknown owner - C:\Windows\system32\locator.exe (file missing)
O23 - Service: @%SystemRoot%\system32\samsrv.dll,-1 (SamSs) - Unknown owner - C:\Windows\system32\lsass.exe (file missing)
O23 - Service: Skype Updater (SkypeUpdate) - Skype Technologies - C:\Program Files (x86)\Skype\Updater\Updater.exe
O23 - Service: @%SystemRoot%\system32\snmptrap.exe,-3 (SNMPTRAP) - Unknown owner - C:\Windows\System32\snmptrap.exe (file missing)
O23 - Service: @%systemroot%\system32\spoolsv.exe,-1 (Spooler) - Unknown owner - C:\Windows\System32\spoolsv.exe (file missing)
O23 - Service: @%SystemRoot%\system32\sppsvc.exe,-101 (sppsvc) - Unknown owner - C:\Windows\system32\sppsvc.exe (file missing)
O23 - Service: @%SystemRoot%\system32\ui0detect.exe,-101 (UI0Detect) - Unknown owner - C:\Windows\system32\UI0Detect.exe (file missing)
O23 - Service: @%SystemRoot%\system32\vaultsvc.dll,-1003 (VaultSvc) - Unknown owner - C:\Windows\system32\lsass.exe (file missing)
O23 - Service: @%SystemRoot%\system32\vds.exe,-100 (vds) - Unknown owner - C:\Windows\System32\vds.exe (file missing)
O23 - Service: @%systemroot%\system32\vssvc.exe,-102 (VSS) - Unknown owner - C:\Windows\system32\vssvc.exe (file missing)
O23 - Service: @%SystemRoot%\system32\Wat\WatUX.exe,-601 (WatAdminSvc) - Unknown owner - C:\Windows\system32\Wat\WatAdminSvc.exe (file missing)
O23 - Service: @%systemroot%\system32\wbengine.exe,-104 (wbengine) - Unknown owner - C:\Windows\system32\wbengine.exe (file missing)
O23 - Service: @%Systemroot%\system32\wbem\wmiapsrv.exe,-110 (wmiApSrv) - Unknown owner - C:\Windows\system32\wbem\WmiApSrv.exe (file missing)
O23 - Service: @%PROGRAMFILES%\Windows Media Player\wmpnetwk.exe,-101 (WMPNetworkSvc) - Unknown owner - C:\Program Files (x86)\Windows Media Player\wmpnetwk.exe (file missing)
O23 - Service: WSWNA1100 - Unknown owner - C:\Program Files (x86)\NETGEAR\WNA1100\WifiSvc.exe
--
End of file - 13383 bytes

Quick update:
I have now removed Real Player (which I wasn't using anyway) and took it off Run list, killed all reference to it.
I also took Live Messinger off Run list since my son suggested it might be sound that someone has logged on.
I closed Skype for same reason.
Still get chimes.
Here's the latest HijackThis:
Logfile of Trend Micro HijackThis v2.0.4
Scan saved at 10:28:12 PM, on 4/20/2012
Platform: Windows 7 SP1 (WinNT 6.00.3505)
MSIE: Internet Explorer v9.00 (9.00.8112.16421)
Boot mode: Normal
Running processes:
C:\Program Files (x86)\Uniblue\RegistryBooster\rbmonitor.exe
C:\Program Files (x86)\Hewlett-Packard\HP Odometer\hpsysdrv.exe
C:\Program Files (x86)\Siber Systems\AI RoboForm\robotaskbaricon.exe
C:\Program Files (x86)\Hp\HP Software Update\hpwuschd2.exe
C:\Program Files (x86)\NETGEAR\WNA1100\WNA1100.exe
C:\Program Files (x86)\Canon\Canon IJ Network Scan Utility\CNMNSUT.exe
C:\Program Files (x86)\LeapFrog\LeapFrog Connect\Monitor.exe
C:\Program Files (x86)\Common Files\Java\Java Update\jusched.exe
C:\Windows\SysWOW64\Macromed\Flash\FlashUtil32_11_2_202_233_ActiveX.exe
C:\Program Files (x86)\Internet Explorer\iexplore.exe
C:\Program Files (x86)\Internet Explorer\iexplore.exe
C:\Program Files (x86)\Trend Micro\HiJackThis\HiJackThis.exe
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = HP MSN.com
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = http://go.microsoft.com/fwlink/?LinkId=54896
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = HP MSN.com
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = HP MSN.com
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = http://go.microsoft.com/fwlink/?LinkId=54896
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = http://go.microsoft.com/fwlink/?LinkId=54896
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = HP MSN.com
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant =
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,CustomizeSearch =
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Local Page =
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Local Page = C:\Windows\SysWOW64\blank.htm
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName =
R3 - URLSearchHook: (no name) - {2d7432c9-a3fd-4ed1-aea9-fbdb12dba4a7} - (no file)
F2 - REG:system.ini: UserInit=userinit.exe,
O2 - BHO: AcroIEHelperStub - {18DF081C-E8AD-4283-A596-FA578C2EBDC3} - C:\Program Files (x86)\Common Files\Adobe\Acrobat\ActiveX\AcroIEHelperShim.dll
O2 - BHO: RealPlayer Download and Record Plugin for Internet Explorer - {3049C3E9-B461-4BC5-8870-4C09146192CA} - C:\ProgramData\Real\RealPlayer\BrowserRecordPlugin\IE\rpbrowserrecordplugin.dll
O2 - BHO: RoboForm BHO - {724d43a9-0d85-11d4-9908-00400523e39a} - C:\Program Files (x86)\Siber Systems\AI RoboForm\roboform.dll
O2 - BHO: Java(tm) Plug-In SSV Helper - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files (x86)\Java\jre6\bin\ssv.dll
O2 - BHO: Windows Live ID Sign-in Helper - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Program Files (x86)\Common Files\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O2 - BHO: URLRedirectionBHO - {B4F3A835-0E21-4959-BA22-42B3008E02FF} - C:\PROGRA~2\MICROS~1\Office14\URLREDIR.DLL
O2 - BHO: Java(tm) Plug-In 2 SSV Helper - {DBC80044-A445-435b-BC74-9C25C1C588A9} - C:\Program Files (x86)\Java\jre6\bin\jp2ssv.dll
O3 - Toolbar: &RoboForm Toolbar - {724d43a0-0d85-11d4-9908-00400523e39a} - C:\Program Files (x86)\Siber Systems\AI RoboForm\roboform.dll
O4 - HKLM\..\Run: [HP Software Update] c:\Program Files (x86)\HP\HP Software Update\HPWuSchd2.exe
O4 - HKLM\..\Run: [PDF Complete] C:\Program Files (x86)\PDF Complete\pdfsty.exe
O4 - HKLM\..\Run: [jswtrayutil] "C:\Program Files (x86)\NETGEAR\WNA1100\jswtrayutil.exe"
O4 - HKLM\..\Run: [Adobe ARM] "C:\Program Files (x86)\Common Files\Adobe\ARM\1.0\AdobeARM.exe"
O4 - HKLM\..\Run: [IJNetworkScanUtility] C:\Program Files (x86)\Canon\Canon IJ Network Scan Utility\CNMNSUT.exe
O4 - HKLM\..\Run: [Monitor] "C:\Program Files (x86)\LeapFrog\LeapFrog Connect\Monitor.exe"
O4 - HKLM\..\Run: [SunJavaUpdateSched] "C:\Program Files (x86)\Common Files\Java\Java Update\jusched.exe"
O4 - HKCU\..\Run: [Backblaze] "C:\Program Files (x86)\Backblaze\bzbui.exe" -quiet
O4 - HKCU\..\Run: [RoboForm] "C:\Program Files (x86)\Siber Systems\AI RoboForm\RoboTaskBarIcon.exe"
O4 - HKUS\S-1-5-19\..\Run: [Sidebar] %ProgramFiles%\Windows Sidebar\Sidebar.exe /autoRun (User 'LOCAL SERVICE')
O4 - HKUS\S-1-5-19\..\RunOnce: [mctadmin] C:\Windows\System32\mctadmin.exe (User 'LOCAL SERVICE')
O4 - HKUS\S-1-5-20\..\Run: [Sidebar] %ProgramFiles%\Windows Sidebar\Sidebar.exe /autoRun (User 'NETWORK SERVICE')
O4 - HKUS\S-1-5-20\..\RunOnce: [mctadmin] C:\Windows\System32\mctadmin.exe (User 'NETWORK SERVICE')
O4 - HKUS\S-1-5-18\..\Run: [Backblaze] "C:\Program Files (x86)\Backblaze\bzbui.exe" -quiet (User 'SYSTEM')
O4 - HKUS\.DEFAULT\..\Run: [Backblaze] "C:\Program Files (x86)\Backblaze\bzbui.exe" -quiet (User 'Default user')
O4 - Global Startup: NETGEAR WNA1100 Smart Wizard.lnk = ?
O8 - Extra context menu item: Customize Menu - file://C:\Program Files (x86)\Siber Systems\AI RoboForm\RoboFormComCustomizeIEMenu.html
O8 - Extra context menu item: E&xport to Microsoft Excel - res://C:\PROGRA~2\MICROS~1\Office12\EXCEL.EXE/3000
O8 - Extra context menu item: Fill Forms - file://C:\Program Files (x86)\Siber Systems\AI RoboForm\RoboFormComFillForms.html
O8 - Extra context menu item: Password Generator - file://C:\Program Files (x86)\Siber Systems\AI RoboForm\RoboFormComPasswordGenerator.html
O8 - Extra context menu item: Save Forms - file://C:\Program Files (x86)\Siber Systems\AI RoboForm\RoboFormComSavePass.html
O8 - Extra context menu item: Se&nd to OneNote - res://C:\PROGRA~2\MICROS~1\Office14\ONBttnIE.dll/105
O8 - Extra context menu item: Show RoboForm Toolbar - file://C:\Program Files (x86)\Siber Systems\AI RoboForm\RoboFormComShowToolbar.html
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files (x86)\Java\jre6\bin\ssv.dll
O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files (x86)\Java\jre6\bin\ssv.dll
O9 - Extra button: @C:\Program Files (x86)\Windows Live\Writer\WindowsLiveWriterShortcuts.dll,-1004 - {219C3416-8CB2-491a-A3C7-D9FCDDC9D600} - C:\Program Files (x86)\Windows Live\Writer\WriterBrowserExtension.dll
O9 - Extra 'Tools' menuitem: @C:\Program Files (x86)\Windows Live\Writer\WindowsLiveWriterShortcuts.dll,-1003 - {219C3416-8CB2-491a-A3C7-D9FCDDC9D600} - C:\Program Files (x86)\Windows Live\Writer\WriterBrowserExtension.dll
O9 - Extra button: Send to OneNote - {2670000A-7350-4f3c-8081-5663EE0C6C49} - C:\Program Files (x86)\Microsoft Office\Office14\ONBttnIE.dll
O9 - Extra 'Tools' menuitem: Se&nd to OneNote - {2670000A-7350-4f3c-8081-5663EE0C6C49} - C:\Program Files (x86)\Microsoft Office\Office14\ONBttnIE.dll
O9 - Extra button: Show Toolbar - {724d43aa-0d85-11d4-9908-00400523e39a} - C:\Program Files (x86)\Siber Systems\AI RoboForm\roboform.dll
O9 - Extra 'Tools' menuitem: Show RoboForm Toolbar - {724d43aa-0d85-11d4-9908-00400523e39a} - C:\Program Files (x86)\Siber Systems\AI RoboForm\roboform.dll
O9 - Extra button: OneNote Lin&ked Notes - {789FE86F-6FC4-46A1-9849-EDE0DB0C95CA} - C:\Program Files (x86)\Microsoft Office\Office14\ONBttnIELinkedNotes.dll
O9 - Extra 'Tools' menuitem: OneNote Lin&ked Notes - {789FE86F-6FC4-46A1-9849-EDE0DB0C95CA} - C:\Program Files (x86)\Microsoft Office\Office14\ONBttnIELinkedNotes.dll
O9 - Extra button: Research - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~2\MICROS~1\Office12\REFIEBAR.DLL
O10 - Unknown file in Winsock LSP: c:\program files (x86)\common files\microsoft shared\windows live\wlidnsp.dll
O10 - Unknown file in Winsock LSP: c:\program files (x86)\common files\microsoft shared\windows live\wlidnsp.dll
O11 - Options group: [ACCELERATED_GRAPHICS] Accelerated graphics
O18 - Protocol: skype4com - {FFC8B962-9B40-4DFF-9458-1830C7DD7F5D} - C:\PROGRA~2\COMMON~1\Skype\SKYPE4~1.DLL
O18 - Protocol: wlpg - {E43EF6CD-A37A-4A9B-9E6F-83F89B8E6324} - C:\Program Files (x86)\Windows Live\Photo Gallery\AlbumDownloadProtocolHandler.dll
O23 - Service: Adobe Acrobat Update Service (AdobeARMservice) - Adobe Systems Incorporated - C:\Program Files (x86)\Common Files\Adobe\ARM\1.0\armsvc.exe
O23 - Service: Adobe Flash Player Update Service (AdobeFlashPlayerUpdateSvc) - Adobe Systems Incorporated - C:\Windows\SysWOW64\Macromed\Flash\FlashPlayerUpdateService.exe
O23 - Service: @%SystemRoot%\system32\Alg.exe,-112 (ALG) - Unknown owner - C:\Windows\System32\alg.exe (file missing)
O23 - Service: Backblaze Service (bzserv) - Unknown owner - C:\Program Files (x86)\Backblaze\bzserv.exe
O23 - Service: @%SystemRoot%\system32\efssvc.dll,-100 (EFS) - Unknown owner - C:\Windows\System32\lsass.exe (file missing)
O23 - Service: @%systemroot%\system32\fxsresm.dll,-118 (Fax) - Unknown owner - C:\Windows\system32\fxssvc.exe (file missing)
O23 - Service: HP Support Assistant Service - Hewlett-Packard Company - C:\Program Files (x86)\Hewlett-Packard\HP Support Framework\hpsa_service.exe
O23 - Service: HP Auto (HPAuto) - Hewlett-Packard - C:\Program Files\Hewlett-Packard\HP Auto\HPAuto.exe
O23 - Service: HP Client Services (HPClientSvc) - Hewlett-Packard Company - C:\Program Files\Hewlett-Packard\HP Client Services\HPClientServices.exe
O23 - Service: HP Quick Synchronization Service (HPDrvMntSvc.exe) - Hewlett-Packard Company - C:\Program Files (x86)\Hewlett-Packard\Shared\HPDrvMntSvc.exe
O23 - Service: HP Software Framework Service (hpqwmiex) - Hewlett-Packard Company - C:\Program Files (x86)\Hewlett-Packard\Shared\hpqWmiEx.exe
O23 - Service: Canon Inkjet Printer/Scanner/Fax Extended Survey Program (IJPLMSVC) - Unknown owner - C:\Program Files (x86)\Canon\IJPLM\IJPLMSVC.EXE
O23 - Service: JumpStart Wi-Fi Protected Setup (jswpsapi) - Atheros Communications, Inc. - C:\Program Files (x86)\NETGEAR\WNA1100\jswpsapi.exe
O23 - Service: @keyiso.dll,-100 (KeyIso) - Unknown owner - C:\Windows\system32\lsass.exe (file missing)
O23 - Service: LeapFrog Connect Device Service - LeapFrog Enterprises, Inc. - C:\Program Files (x86)\LeapFrog\LeapFrog Connect\CommandService.exe
O23 - Service: LightScribeService Direct Disc Labeling Service (LightScribeService) - Hewlett-Packard Company - c:\Program Files (x86)\Common Files\LightScribe\LSSrvc.exe
O23 - Service: @comres.dll,-2797 (MSDTC) - Unknown owner - C:\Windows\System32\msdtc.exe (file missing)
O23 - Service: @%SystemRoot%\System32\netlogon.dll,-102 (Netlogon) - Unknown owner - C:\Windows\system32\lsass.exe (file missing)
O23 - Service: PDF Document Manager (pdfcDispatcher) - PDF Complete Inc - C:\Program Files (x86)\PDF Complete\pdfsvc.exe
O23 - Service: @%systemroot%\system32\psbase.dll,-300 (ProtectedStorage) - Unknown owner - C:\Windows\system32\lsass.exe (file missing)
O23 - Service: @%systemroot%\system32\Locator.exe,-2 (RpcLocator) - Unknown owner - C:\Windows\system32\locator.exe (file missing)
O23 - Service: @%SystemRoot%\system32\samsrv.dll,-1 (SamSs) - Unknown owner - C:\Windows\system32\lsass.exe (file missing)
O23 - Service: Skype Updater (SkypeUpdate) - Skype Technologies - C:\Program Files (x86)\Skype\Updater\Updater.exe
O23 - Service: @%SystemRoot%\system32\snmptrap.exe,-3 (SNMPTRAP) - Unknown owner - C:\Windows\System32\snmptrap.exe (file missing)
O23 - Service: @%systemroot%\system32\spoolsv.exe,-1 (Spooler) - Unknown owner - C:\Windows\System32\spoolsv.exe (file missing)
O23 - Service: @%SystemRoot%\system32\sppsvc.exe,-101 (sppsvc) - Unknown owner - C:\Windows\system32\sppsvc.exe (file missing)
O23 - Service: @%SystemRoot%\system32\ui0detect.exe,-101 (UI0Detect) - Unknown owner - C:\Windows\system32\UI0Detect.exe (file missing)
O23 - Service: @%SystemRoot%\system32\vaultsvc.dll,-1003 (VaultSvc) - Unknown owner - C:\Windows\system32\lsass.exe (file missing)
O23 - Service: @%SystemRoot%\system32\vds.exe,-100 (vds) - Unknown owner - C:\Windows\System32\vds.exe (file missing)
O23 - Service: @%systemroot%\system32\vssvc.exe,-102 (VSS) - Unknown owner - C:\Windows\system32\vssvc.exe (file missing)
O23 - Service: @%SystemRoot%\system32\Wat\WatUX.exe,-601 (WatAdminSvc) - Unknown owner - C:\Windows\system32\Wat\WatAdminSvc.exe (file missing)
O23 - Service: @%systemroot%\system32\wbengine.exe,-104 (wbengine) - Unknown owner - C:\Windows\system32\wbengine.exe (file missing)
O23 - Service: @%Systemroot%\system32\wbem\wmiapsrv.exe,-110 (wmiApSrv) - Unknown owner - C:\Windows\system32\wbem\WmiApSrv.exe (file missing)
O23 - Service: @%PROGRAMFILES%\Windows Media Player\wmpnetwk.exe,-101 (WMPNetworkSvc) - Unknown owner - C:\Program Files (x86)\Windows Media Player\wmpnetwk.exe (file missing)
O23 - Service: WSWNA1100 - Unknown owner - C:\Program Files (x86)\NETGEAR\WNA1100\WifiSvc.exe
--
End of file - 12812 bytes

Still chiming. I'm at my wits end with this. What could it be?

Another report:
Well, the phantom sound has been identified as one from process named TkBell (which I assume is Tinker Bell) and appears to be associated with Real Player. I removed Real Player, reinstalled it, and removed it all again. I also took the TkBell entry from the Run on startup and can no longer find it anywhere.
But it still pops out from time to time (particularly right after booting up) and I suspect it is a Windows sound that is used by other processes.
I have also disabled Live Messenger, which I nevered used and suspect using it for notifications or users logging in or out.
If anyone knows TkBell, and where it lives, I'd like to know. I am going to try and attach this sound (I have the wav file) to this point, but it that isn't supported I can e-mail it anyone who might be interested.
Thanks for all the help.

I attached a short wave of the TkBell wave file. The problem is I don't know what programs are using it. The process is no longer running and I have purged Real Player from my system (cleaning registry, start up lists, libraries, etc.) and I think I got 'em all.
Boy, some of these programs are hard to remove. And shared resources (like this wave file) are really hard to get rid of.