Desktop restarting when going into standby?

[DistressedUser]

Windows XP
AMD Athlon 64 X2 Dual
2.61 GHz, 2.00 gb ram
NVIDIA GeForce 8600

Since last week, if I leave the computer for around 30 minutes+ (usual time for computer to go into hibernation? standby? A bit confused on the difference), it automatically restarts itself. Then Windows tells me it has recovered from a serious error. This began after my Norton found a trojan during a background system scan, but I don't think this has much to do with it; there was only one trojan, and I scanned with Avast AND Norton afterward just to make sure it was gone.

I have checked the drivers and don't see any of them needing updates, etc. One thing I thought of that could be part of this is that I recently got a new mouse. It is a rechargeable mouse that goes in a cradle. Since the mouse died, but the cradle and such still work, I got a mouse that still works and use it for that cradle, and it works fine. A few days before I got the new mouse (sans cradle) I used a simple usb plugin mouse.

I checked to see the standby/hibernation/monitor settings, and everything is turn off, except the monitor shuts off after 20 minutes. I have disabled this, for now, but I usually turn off the monitor if I leave it for a little while.

This is most likely a video card error, right?

[glc]

Control panel, system, advanced. Startup and recovery - uncheck restart on error. This should give you a BSOD instead of a reboot, read the screen for clues.

[DistressedUser]

I'll try this, thanks for replying. However, I've left my desktop alone for more than an hour, and I've had it on for a few hours today, and so far nothing. It hasn't gone into standby or anything, so there haven't been any problems.