once it's uninstalled, reboot at least twice - making sure that the Windows Firewall is switched on - and then run MGADiag again and post the new report.
If it's fixed then we've at least identified the problem - and you can decide what to do about Comodo later.
If it's still a problem then at least we've eliminated a possible cause, and can think about where else to look.
Uninstalled COMODO and right away I had sound and my copy of Windows is happy and satisfied. 
Turned on my Windows Firewall ... I may have hit "restore defaults" and whether that's the case or not, I can't get online and I don't know how to fix it (I'm posting this from my little Linux netbook).
Here's the new MGADiag results, courtesy of my trusty flash stick:
Code:
Diagnostic Report (1.9.0027.0):
-----------------------------------------
Windows Validation Data-->
Validation Code: 0
Cached Online Validation Code: 0x0
Windows Product Key: *****-*****-JY4GC-RTMYW-F4YM7
Windows Product Key Hash: zricHvlvFuCjn+dTuY+u2v8sHj0=
Windows Product ID: 00371-OEM-9045415-49483
Windows Product ID Type: 3
Windows License Type: OEM System Builder
Windows OS version: 6.1.7601.2.00010100.1.0.048
ID: {6A12470F-834E-4870-91E2-ADFF5F285114}(3)
Is Admin: Yes
TestCab: 0x0
LegitcheckControl ActiveX: N/A, hr = 0x80070002
Signed By: N/A, hr = 0x80070002
Product Name: Windows 7 Professional
Architecture: 0x00000009
Build lab: 7601.win7sp1_gdr.140303-2144
TTS Error:
Validation Diagnostic:
Resolution Status: N/A
Vista WgaER Data-->
ThreatID(s): N/A, hr = 0x80070002
Version: N/A, hr = 0x80070002
Windows XP Notifications Data-->
Cached Result: N/A, hr = 0x80070002
File Exists: No
Version: N/A, hr = 0x80070002
WgaTray.exe Signed By: N/A, hr = 0x80070002
WgaLogon.dll Signed By: N/A, hr = 0x80070002
OGA Notifications Data-->
Cached Result: N/A, hr = 0x80070002
Version: N/A, hr = 0x80070002
OGAExec.exe Signed By: N/A, hr = 0x80070002
OGAAddin.dll Signed By: N/A, hr = 0x80070002
OGA Data-->
Office Status: 109 N/A
OGA Version: N/A, 0x80070002
Signed By: N/A, hr = 0x80070002
Office Diagnostics: 025D1FF3-364-80041010_025D1FF3-229-80041010_025D1FF3-230-1_025D1FF3-517-80040154_025D1FF3-237-80040154_025D1FF3-238-2_025D1FF3-244-80070002_025D1FF3-258-3
Browser Data-->
Proxy settings: N/A
User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Win32)
Default Browser: C:\Users\Raenna\AppData\Local\Google\Chrome\Application\chrome.exe
Download signed ActiveX controls: Prompt
Download unsigned ActiveX controls: Disabled
Run ActiveX controls and plug-ins: Allowed
Initialize and script ActiveX controls not marked as safe: Disabled
Allow scripting of Internet Explorer Webbrowser control: Disabled
Active scripting: Allowed
Script ActiveX controls marked as safe for scripting: Allowed
File Scan Data-->
Other data-->
Office Details: <GenuineResults><MachineData><UGUID>{6A12470F-834E-4870-91E2-ADFF5F285114}</UGUID><Version>1.9.0027.0</Version><OS>6.1.7601.2.00010100.1.0.048</OS><Architecture>x64</Architecture><PKey>*****-*****-*****-*****-F4YM7</PKey><PID>00371-OEM-9045415-49483</PID><PIDType>3</PIDType><SID>S-1-5-21-939792234-235047099-4049540723</SID><SYSTEM><Manufacturer>To Be Filled By O.E.M.</Manufacturer><Model>To Be Filled By O.E.M.</Model></SYSTEM><BIOS><Manufacturer>American Megatrends Inc.</Manufacturer><Version>P1.20</Version><SMBIOSVersion major="2" minor="6"/><Date>20111117000000.000000+000</Date></BIOS><HWID>AEA20200010000FC</HWID><UserLCID>0409</UserLCID><SystemLCID>0409</SystemLCID><TimeZone>Eastern Standard Time(GMT-05:00)</TimeZone><iJoin>0</iJoin><SBID><stat>3</stat><msppid></msppid><name></name><model></model></SBID><OEM/><GANotification/></MachineData><Software><Office><Result>109</Result><Products/><Applications/></Office></Software></GenuineResults>
Spsys.log Content: 0x80070002
Licensing Data-->
Software licensing service version: 6.1.7601.17514
Name: Windows(R) 7, Professional edition
Description: Windows Operating System - Windows(R) 7, OEM_COA_NSLP channel
Activation ID: e120e868-3df2-464a-95a0-b52fa5ada4bf
Application ID: 55c92734-d682-4d71-983e-d6ec3f16059f
Extended PID: 00371-00180-454-149483-02-1033-7601.0000-1752014
Installation ID: 014973207141674120786071456743009126706951938600873635
Processor Certificate URL: http://go.microsoft.com/fwlink/?LinkID=88338
Machine Certificate URL: http://go.microsoft.com/fwlink/?LinkID=88339
Use License URL: http://go.microsoft.com/fwlink/?LinkID=88341
Product Key Certificate URL: http://go.microsoft.com/fwlink/?LinkID=88340
Partial Product Key: F4YM7
License Status: Licensed
Remaining Windows rearm count: 3
Trusted time: 6/27/2014 4:29:23 PM
Windows Activation Technologies-->
HrOffline: 0x00000000
HrOnline: 0xC004C533
HealthStatus: 0x0000000000000000
Event Time Stamp: 6:23:2014 22:22
ActiveX: Registered, Version: 7.1.7600.16395
Admin Service: Registered, Version: 7.1.7600.16395
HealthStatus Bitmask Output:
HWID Data-->
HWID Hash Current: MgAAAAEABAABAAEAAAACAAAAAQABAAEAln0mUehqwAgaSFTyEDNcyLSbYj3ogtoEyGA=
OEM Activation 1.0 Data-->
N/A
OEM Activation 2.0 Data-->
BIOS valid for OA 2.0: yes, but no SLIC table
Windows marker version: N/A
OEMID and OEMTableID Consistent: N/A
BIOS Information:
ACPI Table Name OEMID Value OEMTableID Value
APIC ALASKA A M I
FACP ALASKA A M I
HPET ALASKA A M I
MCFG ALASKA A M I
AAFT ALASKA OEMAAFT
SSDT AMD POWERNOW
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