Problem with Graphics, Nividia 9800 GTX

First let me say thanks for any help I can get, I haven been trying to fix this problem for a bit now and am turning up no results

I have been having card problems for a week now, I have been doing Models pretty intense for a class project during that time and it is during this time the problem started

It started as a blue screen I would get after being in my 3D modeling program for a couple of hours ever few days or so, it was NV4_disp.dll, I looked it up and found it was a Nividia Driver problem, made scence because the last driver I made the mistake of installing through windows update and not the sight. So I tried a manual uninstall of the drivers and I thought it fixed the problem but I got the screen again a few days later, and now when I try to play Left 4 Dead I will get graphical lock ups every few minutes (the screen freezes and the sound effects that where playing when it happen loop until it unfreezes). This is on top of the other minor but annoying graphical errors I have been getting when modeling

My Driver unistall process

I go into the Nividia directory in the C drive, then into the WinXP file and delete the driver files

I go into Hardware manager and uninstall my video card from under Display Adapters

Reboot my computer

After reboot when it ask to install new hardware I stop it and install the newest driver manually from the desktop where I downloaded it before starting

Then restart the computer

I don't know if it is my process or my vid card, I don't have any problem with World of Warcraft so it leads me to believe it is just things that work the card hard, LFD was really bad last night but that was after working in my modeling environment for over 7 hours strait, when I tried LFD this morning after turning the computer on for the first time today it still locked up but not as long and not as often, maybe 3 times for a few seconds in a 5 minute game

Any help would be greatly appreciated

You could try DriverSweeper I think its called