Windows 7 flashing

First sorry if this went in the wrong section.

My windows 7 ultimate is just flashing. and I cant do anything at all. it does it even in safe mode if a bit slower. I have tried to restore it to a previous save using the Install CD but it always gives an unknown error when I do so. I also tried booting to "last known good configuration".

Any ideas is appreciated...

It's flashing as in the screen is flickering? Did this happen randomly? My first thoughts would be GPU or Monitor. If you could give more information. It would be appreciated. That way, people will be able to better advise you with the current situation.

its a constant flashing like its refreshing. in safe mode where the flashing is slower every flash closes all the open windows and reorganizes the desktop. I cant even open anything when its on the normal startup. I really don't know what other info I can give, sorry. It just started today for some reason.

Try swapping your monitor out. If this don't work . Try swapping your out your video card out if possible.. Have you updated your video drivers lately? Installed any new software?

no new software installed within the last 2 weeks ... but its all moot now as I must have done something last night as I cant get to the desktop anymore.... It seems I really have to reinstall the OS now.