Let me know if this stops it

Clear Cache/Temp Files
Download TFC by OldTimer to your desktop

[*] Please double-click TFC.exe to run it. (Note: If you are running on Vista, right-click on the file and choose Run As Administrator).
[*]It will close all programs when run, so make sure you have saved all your work before you begin.
[*]Click the Start button to begin the process. Depending on how often you clean temp files, execution time should be anywhere from a few seconds to a minute or two. Let it run uninterrupted to completion.
[*]Once it’s finished it should reboot your machine. If it does not, please manually reboot the machine yourself to ensure a complete clean.

THEN

CAUTION : This fix is only valid for this specific machine, using it on another may break your computer

Download the attached Fixlist.txt to the same location as FRST
Run FRST and press Fix
On completion a log will be generated please post that