No 3d for me

[CaesarSalad]

Well I finally got to upgrading my k6-550 system to the system I slapped together in my sig. Everything went so smoothly I decided to reward myself with a new game (new to me). I bought C&C Generals. Guess what though? It doesn't work on my system. I got crashes, boots to the desktop, and my favorite-the serious error message. The most I got was about 10 minutes playing time. I did some research and found this is not the most stable game on the planet. I also noticed I was getting some errors with my directx9- dxdiag kept telling me i needed to reinstall because my reg was screwy (WinXP is my OS by the way). So, I decided since I never gave it a whack with dx8.1 to format and try a fresh install. Now the damn thing won't even run let alone crash. Here's where I'm worried. None of the games I've tried run. Pool of Radiance- crash to desktop! Dungeon Siege-crash to desktop or hard lock-up! Thief 1 -reboots my system! As you can tell by the games I've mentioned I'm not a hardcore gamer. But I do enjoy the occasional diversion of time. Here's what I've tried:

Original BIOS-Updated BIOS
Various ATI drivers
Various game patches-incremented and lastest versioned
Tweaking video settings (AGP4x, AA, Vertical Sync, etc.)
Directx8.1 - 9
memtest-no problems reported
underclocking
voltage tweaks-this was the only thing that had an impact. default is 1.65 bumped to 1.75- it took longer for crashes to occur at this setting. Other settings made my system unstable.

Other than game crashing my system is bullet proof. I can burn files, have 8 + browser windows open, download 6 simultaneous files with Dap while writing a letter with Word with nary a slowdown. I can run 3dMark03 all day long. But when I run a game, barf! No viruses. Minimal apps run when I try to load a game. I'm fairly competent with my system and hardware in general, but this has got me scratching my noggin. Any advice?

 

[DAPUNISHER]

I would start by disabling 8x AGP support and fast writes in the bios while enabling vid ram caching, and be certain fastwrites is disabled in the control panel under the SMARTGART tab too. Next, if need be, I would try 1 stick of ram at a time in both slot 1&2, bump up the vDIMM, relax timings, and run memtest86 on each stick to determine if dual channel or a faulty stick are behind the problems. I'd investigate your chipset cooling and load fail-safe bios settings too just to take as much out of the mix as possible.