You can rotate/flip your screen by accessing your video graphics adapter control center application.
If u have ATi series VGA then start ATi Catalyst Control Center and u will find there that option.
If u have Nvidia series VGA then start Nvidia Control Panel
these applications (control centers) have a tray icon on windows task bar ( on the right where the clock is) so u can access them quickly .. (some nvidia control centers can be accessed by right clicking on desktop and then clicking Nvidia control panel from that menu *its usually above NEW and under REFRESH option*)
When u find that options for rotating/flipping in control panel of your vga , you can even assign them with keyboard shortcuts...
Hope this helps...
Probably the easiest trick in the book but how do you turn your computer screen sideways or upside down?? I've seen my friend do it to others by just clicking two buttons but I'm not sure which ones..