Windows 7 is outside my sphere so far.
However, I think the display drivers may not be doing their stuff.
If so the computer is trying to give you a default image from the integrated video part of the motherboard.
If Control Panel > Systems > Hardware> Device Manager applies in W7, then see what shows under Display Adapters.
If there is a yellow triangle with an exclamation mark, your system either cannot find the GForce7300s, either the drivers have become corrupt or the card itself has come adrift or died.