Are you sure you are adware & malware clean??
See this article:Taking out the Trash
Have you tried a complete cleaning to see if that helps?
Show all Files & Foldershttp://www.bleepingcomputer.com/forums/ind...showtutorial=62
Try these free tools.
Trendmicro (free virus scan only)http://housecall.trendmicro.com/
Ewido (free Trojan Scanner)http://www.ewido.net/en/download/
Adware SE (update after installing)http://www.lavasoftusa.com/software/adaware/
Spybot S&D (update after installing)http://www.download.com/Spybot-Search-Dest...4-10122137.html
Go to the Device Manager and Remove the Display Adapter & Restart your computer and let Windows reinstall it drom the Driver Cache.
Right Click My Computer>Device Manager Tab>Click the + sign by Display Adapter>Click on the Adapter>Remove>Yes>Restart
If you are using after market video card you can find the drivers at the manufactures website.