Windows 7 periodically Freezes.

My windows 7 64-bit Pro computer has a nasty, annoying problem. I’m pretty sure it’s been present since I built it 2+ years ago. The computer sort of “freezes” periodically and randomly. It can happen two or three times a day or not be seen for 2 days in a row. When it “freezes,” here’s what happens. The mouse moves freely but applications can neither be opened nor closed. Clicking on anything has no effect for the duration of the “freeze.” The length of time a freeze lasts is typically about 30 seconds but can be shorter or longer. Often freezes will occur twice in a row with 10 seconds between freezes. When a freeze occurs, the hard drive lite is ON-SOLID with no flickering for the duration of the freeze. Curiously, audio and video players continue playing during a freeze. I also get application hangs on this computer but I can’t tell if these are related to the “freezes.” Here’s what I’ve done to debug:
· I’ve run process explorer to see what is keeping the hard drive lite on solid but it says the hard drive is free during a freeze. I think process explorer is tell the truth because I can’t hear any drive activity during a freeze. I suspect the hard drive lite is not really reflecting HD activity during a freeze.
· I’ve updated my video drivers a few times with no effect on the freezes.
· I suspected the Sata Drivers which I understand are part of the Intel chipset INF drivers. I ran the Intel Driver Update Utility which indicated I have version 9.1.2.1007 and that “This version is valid.”
· I ran SFC /verifyonly but no problems were found.
Also, no errors are logged in the event viewer as a result of a freeze. At the bottom of the post I listed informational events that occur with a freeze.
All help will be appreciated!

Code:

Windows 7 professional 64 bit 
CPU: i7-870
Mobo: Gigabyte GA-P55-USB3 (rev 2) 
Memory: G.Skill F3-10666CL8D-4GBHK; (4GB)
Graphics Card: Radeon HD4670 
Hard Drives:
· VelociRaptor WD1500HLFS 150GB (system+applications)
· 2TB Samsung spinpoint (data) 
· WD caviar blue (data)
PSU: Antec EA-500D Earthwatts 
Other: Hauppauge TV Card HVR-1600
 
Informational events logged with a "freeze:"
Log Name:      System
Source:        Service Control Manager
Date:          9/15/2012 12:29:52 PM
Event ID:      7036
Task Category: None
Level:         Information
Keywords:      Classic
User:          N/A
Computer:      FASTEDDIE
Description: The Windows Error Reporting Service service entered the stopped state.
-
Log Name:      System
Source:        Service Control Manager
Date:          9/15/2012 12:28:45 PM
Event ID:      7036
Task Category: None
Level:         Information
Keywords:      Classic
User:          N/A
Computer:      FASTEDDIE
Description: The Application Experience service entered the running state.
-
Log Name:      System
Source:        Service Control Manager
Date:          9/15/2012 12:27:52 PM
Event ID:      7036
Task Category: None
Level:         Information
Keywords:      Classic
User:          N/A
Computer:      FASTEDDIE
Description:  The Windows Error Reporting Service service entered the running state.
-
Log Name:      Security
Source:        Microsoft-Windows-Security-Auditing
Date:          9/15/2012 12:27:47 PM
Event ID:      4672
Task Category: Special Logon
Level:         Information
Keywords:      Audit Success
User:          N/A
Computer:      FASTEDDIE
Description:
Special privileges assigned to new logon.

Subject:
                Security ID:                             SYSTEM
                Account Name:                      SYSTEM
                Account Domain:                   NT AUTHORITY
                Logon ID:                               0x3e7

Privileges:                              SeAssignPrimaryTokenPrivilege
                                                SeTcbPrivilege
                                                SeSecurityPrivilege
                                                SeTakeOwnershipPrivilege
                                                SeLoadDriverPrivilege
                                                SeBackupPrivilege
                                                SeRestorePrivilege
                                                SeDebugPrivilege
                                                SeAuditPrivilege
                                                SeSystemEnvironmentPrivilege
                                                SeImpersonatePrivilege 
-
Log Name:      Security
Source:        Microsoft-Windows-Security-Auditing
Date:          9/15/2012 12:27:47 PM
Event ID:      4624
Task Category: Logon
Level:         Information
Keywords:      Audit Success
User:          N/A
Computer:      FASTEDDIE
Description:
An account was successfully logged on.

Subject:
                Security ID:                             SYSTEM
                Account Name:                      FASTEDDIE$
                Account Domain:                   WORKGROUP
                Logon ID:                               0x3e7

Logon Type:                                          5

New Logon:
                Security ID:                             SYSTEM
                Account Name:                      SYSTEM
                Account Domain:                   NT AUTHORITY
                Logon ID:                               0x3e7
                Logon GUID:                         {00000000-0000-0000-0000-000000000000}

Process Information:
                Process ID:                            0x260
                Process Name:                      C:\Windows\System32\services.exe

Network Information:
                Workstation Name:               
                Source Network Address:     -
                Source Port:                           -

Detailed Authentication Information:
                Logon Process:                     Advapi  
                Authentication Package:       Negotiate
                Transited Services:               -
                Package Name (NTLM only):               -
                Key Length:                            0

Have you ran a full virus scan, I would install and update Malwarebytes, and run it while in safe mode. Then you can try doing a minimal boot using MSConfig, just make sure you don't disable Microsoft processes. Also do a hard drive test to make sure your drive is working fully. Depending on the brand of your Hard Drive, I would get the diagnostics program from the manufacturer's website.

they told you to test each ram bank alone to find easily who of the two was faulty. Figuring out those addresses is something not a lot of techs can (or feel the need to) do.

So, test ONE RAM bank at a time, once in a ram slot, once in the other.

Check the ram voltage in the bios with the ram voltage needed (should be stated on the manufacturer's site or on the RAM's documentation), and adjust it if necessary.