Ok this is kinda hard to explain but while im lets say playing a song, Surfing the net, and then go to search through my harddrive sometimes (not all the time) the screen will immediately become oversized like the resolution is completely wrong...or having some kind of video problem conflict....When this happens i have to restart my computer because the objects are to huge and go off the screen so i cant close anything.  One time i was able to close media player and that resolved the problem and the screen went back to normal??? Does this make sense to you guys i dont really know how else to explain it.  I have a xps 400, dualcore 3.0 intel, 7800 GTX, 1GB ram, Ultrasharp 17" monitor

I've only had the computer a little over a month now.  It comes out of no where when it happens i can still use my mouse and tab stuff up but things are huge such as; icons, task window, etc

Has anyone else came in contact with this problem?

How can i fix it?