Hi John,
There might be a chance that there is some system file corruption. So, I would suggest you to run
SFC scan and see if it brings any difference.
System file check is a utility built into the Operating System that will check for system file corruption. The sfc /scannow command (System File Check)
scans the integrity of all protected operating system files and replaces incorrect, corrupted, changed, or damaged versions with the correct versions where possible.
How to use the System File Checker tool to troubleshoot missing or corrupted system files on Windows Vista or on Windows 7.
- Go to Start, click All Programs and open Accessories.
- Right click on Command Prompt in the Program list and then select
Run as administrator. If you are prompted for an administrator password or for confirmation, type your password, or click
OK.
- In the Command Prompt, type the following command, and then press ENTER:
sfc /scannow
For more information refer to this link:
http://support.microsoft.com/kb/929833/en-us
Do keep us updated.
Regards,