check your resulution and colors..
how it set?
Try this:
http://www.sevenforums.com/tutorials/2495-services-start-disable.html
>Start
>Search "msconfig"
>Right click
>Click "Run As Administrator"
>Services Tab
> Scroll down and make sure a checkbox is ticked next to "Themes" and "Desktop Window Manager Session Manager".
Then
>Start
>Search "services"
>Open Services result
>Scroll down and make sure "Themes" and "Desktop Window Manager Session Manager" are started, if not, right
click
> Start.
If they are disabled,
>Right click
>Properties
>Startup Type set to "Automatic" then start them.
Do this for both.