Win 7 showing disfigured graphics

today when i was working on excel at the same time ws surfing.
suddenly my excel started showing 2 red coloured bars from one end to another. when i ws clicking on diffrent cells the bars were moving up and down.
so then i close excel.

but after some time my w7 desktop started funny activity the clock on the right top my screen was scattred,
it was like what a old tv do when signal is not clear.
then it started happening to whole screen.

now i an using my backup window Xp, and it is working fine.

Guys plz help what this could this be.

could it be my gpu nvidia 9500 coz i overclocked it by 10%. and that was two days back and i did it for about 2 hrs only now my gpu temp is showing around 47 c when playing game.

my config is intel E7500 2.93 Gz, 4 GB DDR2 Ram, gfrc 9500 1 GB GPU

Try uninstalling your display drivers in win7 then sweep it again with driver sweeper or driver cleaner . do a restart and install latest stable drivers of your device. since you mentioned overclocking i would suggest you to try running the gcard on stock settings. Run it on stock settings for a few days and if everything seems fine then try overclocking . also i would suggest to check the signal cable which connects the monitor to your gcard. ive seen a couple of cases where this wire was broken/loosened internally . try jiggling it a little and check for immediate colour changes. Hope this helps .