New gamer needs tech help!

Im a pretty advanced computer user but just getting into serious gaming. I have a self built computer-
Gigahertz Thunderbird,
Shuttle AK11 MoBo,
256mb SDRAM,
Cardexpert Gforce 2 Mx400 64mb with Detonator drivers,
dual boot Win 98SE/Windows 2000,
Sound Blaster Live.

I havent had any problems until I installed the Castle Wolfstein demo in 2000. It played good but the mouse action was jerky so I went into the options to adjust it. As soon as I moved the adjusting slider I got the black screen and a memory error. I rebooted and tried again but as soon as I moved the slider the computer rebooted. It started to boot into 2000 but then kept rebooting. I couldnt even get into safe mode. I tried booting into 98 and it started installing all the motherboard drivers and hardware like I had just installed the mobo. Finally 98 came up and worked fine. Long story but I could never get back into 2000, just formatted the partition and reinstalled. Now I installed the the full version of Elite Force. I go into options to adjust the video and as soon as I moved the video slider theres a click and the computer reboots. Now Im afraid to play any games because Im stumped. Elite played great on my last computer. This is the only problem Ive had with this new one. Thanks. Oh, I have all the latest hardware and software drivers and updates.

Have you tried any other games such as UT ? Or have you tried any other apps that may cause this. Is the computer working fine except when you run the games ?? No other errors or BSOD's ??

The first error message is the only one Ive ever gotten with this machine. 2000 is running like a champ. I do alot of MP3 encoding, decoding, ripping, streaming. Even AOL runs better and thats a miracle in itself. I dont want to try any other games until I get a handle on this. I have a feeling its the video drivers but I thought the Detonator drivers were rock solid.

Try searching the forums, especiallly this one. There are alot of issues with the GeF's lately. Read them and see if those answer any of your questions. Have you tried using the next latest driver ? Not the newest but one or two versions before ??

Disable the auto-reboot feature of Windows 2000. When the BSOD happens see what the problem was. Could be a driver problem, or even power related perhaps.