Check your graphic card settings. I have a 6600gt, and can invert my screen. Try going: right click your desktop, select properties. Go the settings tab. Clieck advanced. There do you have a tab for your graphics card? Mine shows I have a 6600Gt. After selecting the tab it displays options. I have NVrotate. That rotates my screen.
So, what hardware do you have?
Apathy: If we don't take care of the customer,maybe they'll stop bugging us.
Customer Disservice: Because we're not satisfied until you're not satisfied.
(Maybe BB's approach?)