Pixelated textures after Avast! install

[AdrianH]

http://windows.microsoft.com/en-gb/windows-vista/troubleshoot-monitor-and-video-card-problems

https://www.google.co.uk/search?client=opera&q=windows+7+pixelated+screen&sourceid=opera&ie=utf-8&oe=utf-8&channel=suggest

[Greatmar2]

http://windows.microsoft.com/en-gb/windows-vista/troubleshoot-monitor-and-video-card-problems

https://www.google.co.uk/search?client=opera&q=windows+7+pixelated+screen&sourceid=opera&ie=utf-8&oe=utf-8&channel=suggest

Sorry, these are all pretty much saying I should reinstall/update my graphics drivers. The prior I have done, which didn't work. The latter can't be done, as windows says it has a custom driver.