Weird Lines on Screen

The other day out of nowhere my screen starts going nuts. It has a bunch of horizontal and vertical lines on the screen and they kind of move when the mouse is over them. When I open a new window, for example an AIM window or Notepad, parts of the program will display fine, without any lines, and other parts will continue the line pattern on the screen. When my computer starts up, it has weird gray images that almost look like Japanese letters on the Windows XP splash screen. I checked a different monitor and the picture is still weird, so it isnt monitor, so Im guessing its video card...? Anyone ever heard of a problem like this?

Thanks a lot.