My computer is a P4 2.66GHz running XP with the latest updates from Microsoft and 1G of memory. About 2 months ago I upgraded my video card to an Nvidia 6600 series card (friend upgraded and I got it free). I downloaded and installed new drives.

My computer works fine for most tasks... standard office tools, email, internet and some computer games... C&C2. With C&C3 I had to manually de-tune graphics capability to prevent lockup. With newer games like Orange Box, I get about 2 minutes of play before lockup. I then started looking at older games that I played in the past (Oblivion, Civ 4 and Halflife 2) and noticed that they lock my machine up as well. The more graphics a program uses, the faster it locks up/

It appears something is wrong with my settings, but I can't figure it out.

Help.

Rodandy...

I think it couldn't hurt to ungrade your Java

Then go to ADD/REMOVE programs and delete older versions

Download Free Java Software - Sun Microsystems

Maybe you are running too many programs --- or one program may be conflicting

Using Start --->RUN --->msconfig --->System Configuration Utility ---> Startup Tab

Temporarily disable programs one at a time --until you find out which one is at fault

Could be that it's a temperature issue. Make sure that your power supply fan and your processor fan are operating normally. If the video card has a fan check that too.

Could also be that your video card can't keep up with the fps required for the game( I play c&c zh with my nvidia 5200fx card but it goes to slow motion after 3 minutes... I need a new psu)

I believe the fans are OK. My computer stays on all the time unless I'm on travel for more than a couple of days and runs fine given the limitations listed below. I don't think the card has a fan, but I'll check.

The computer comes back up immediately when I reboot and runs for about the same period before crashing. Again, Orange Box locks up in under two minutes. Civ 4 will run for 20-30 minutes before it locks. Bioshock is very jittery and crashes in about 3-4 minutes. Oblivion runs for about 5 minutes. C&C3 does not lock up, but the video settings are de-tuned. C&C Generals runs fine. Yeah, I know. Don't play games so much.

Slowing down... C&C3 does slow down, but only during situations where significant numbers of units are in play or something major (like a nuke going off) happens... and it almost never locks up the machine.

Rod...

I checked the fans last night and there was a fan on the 6600 card. Both that fan and the computer fan were running.

My computer had rebooted and there was a Microsoft message saying something to the effect that there had been a serious error on my system which had required it to shut down. It directed me to a page that said there was an incompatibility between windows and my video card. I was directed to the Display properties Control panel page, Settings, Advanced, and Troubleshooting. The message said I should move the Hardware acceleration slide bar to None and Un-check the Enable write combining box. This sounded like disconnecting the video card, so I only moved the slide down a couple of notches and unchecked the box. I began playing Civ 4 and noted that the mouse cursor was jittery, but usable. The system crashed in about 10 minutes.

It sounds to me like the drivers weren't up to snuff,Microsoft has a knack for that... got to jaton.com and download the current drivers for the card and you won't have that problem again