Recently, I have upgraded my computer, keeping only the 8800 gt. The specs are:
AMD Phenon II X4 965 @ 2.4 ghz
1.25 TB HDD
2 gigs ddr3 ram @ 1333 mhz
Rosewell 1000watt psu
ASUS VW246H 24" monitor
Windows 7 64 bit
Since upgrading, I have huge issues playing almost any game. Call of Duty 4 has strange lag periods followed by artifacts eventually appearing after about 20 minutes of game time. Team Fortress 2 simply crashes once I'm on a server after about 5 minutes. Medieval 2 can run without artifacts(at least based on my limited playing time) but has the same strange hangups every several minutes. The only game I can run decently is Empire:Total War, and even that has strange monitor flicker and after a while of game time the icons start getting messed up. In both Call of Duty 4 and Team Fortress 2, I have seen messages that "Nvidia Driver 197.13 has stopped responding and has recovered".
I at first thought this was an overheating issue, but with EVGA Precision, I saw that the temperature of my card stayed around 62 degress celsius and the fan never went above 30 percent. I increased the fan to 100 percent, but that made no difference.
^ Well you can try updating the drivers...And how old is that card ? You can try RMA...
If you will be going with a new card, then the HD 5850...you can get them for ~$290 and these are as powerful as the GTX 285 and are DirectX 11...
I have heard before that older Nvidia video cards, dunno about ATi, when updated to the more recent drivers w/ make that card obsolete and cause problems. By this happening, it will lead you to think you need a new card. Again this is all hear-say.
But try to rollback your drivers to a previous date and see if the problem still occurs.
I assume you had to do a clean install. By default, Direct X with Windows 7 does not install all the old components of Direct X that many previously release games use. By downloading this and running it, you will get all the appropriate patches for each old version of Direct X. Hopefully, this will solve your issue (along with the most recent Video Drivers).