Here's a patch that should fix the crashing:
http://www.amd.com/products/cpg/athlon-duron/amd_win2k_patch.html
 
I'm pretty sure that should fix things for you.

I can definitely relate. I've been lurking here for a bit, tried every solution I could find here and many other places. For me openGL and D3D both hang my system after several minutes of play.
 
I also get random hangs just on the desktop. Sometimes a few an hour, sometimes several days in between. Although it seems to maybe be related to playing aucio and video.
 
Here's amy setup:

A7A266 (Based on ALiMAGiK1)
TB 1.2GHz
256MB DDR
geForce2 MX 400
Turtle Beach Santa Cruz
HP 8250i (Not the overclockable one )
LG DVD Rom
USB HP 930c
USB Keyboard
USB IntelliMouse Optical
[/list:u]
 
Here is what I have done so far:

Upgraded to SP2
DX8a to 8.1 Beta
Bios to 1007 (I think. Whatever one is in Beta)
SB Live! to Santa Cruz
No Fast Writes
1x AGP
nVidia 12.60 drivers
Disabled all hardware based power saving
Applied the AMD patch
Applied the CDCreator 5 patch
[/list:u]
 
Some things I've noticed on this site and others are, it always seems to be PC's with AMD, ASUS, and nVidia. Perhaps I'm over generalizing it but...

Brian: I'll download that patch as soon as possible.
 
99CobraCvt: I was not aware of DirectX 8.1 Beta, if you could supply a link that would be great. But I do question your use of AGP 1X. I noticed a rather large performance increase when the VIA 4in1 drivers gave me use of AGP 4X. I really need the extra bandwidth for Tribes 2.

I can't remember where I got the DX beta from. I know it was a beotch, as MS apparently got rather upset. lol If you have an FTP site or something I can send it to you. I haven't noticed any changes or improvements though.
 
I am just trying the 1x AGP to see if it stabalized my system. Didn't phase it. The 4 in 1 doesn't applie to me, as I am using the ALi chipset. :-/
 
Let me know if the AMD patch fixed your issue. If it did, then we have different underlying issues.

The ALi chipset is fairly new and not a mature chipset yet, so I wouldn't be surprised if that was causing some problems. I'd read a roundup of mobo's with the Magik1 chipset, and it seems that ALi has some work to do yet. I've not been a real fan of ALi, but still, I figured you might just want to know that. You may try to see if there's a BIOS update for the board, since Asus is pretty regular with new BIOS's.

So after some more thought, I figured that it might be my sound card because 99CobraCvt said that he replaced his sound card and I remembered that a friend of mine had some serious problems with his Athlon and sound card. So I broke out my old MX300 and when I booted into Windows it seems fine but when ever I try and play a game that uses DirectX or OpenGL my sound dies. Using software rendering this does not happen.
 
This is really driving me insane. I am really thinking of dumping this Athlon and picking up a P4.

Probably a stupid question but did you format and reinstall when you upgrading? If not that could be a problem, I know Windows doesn't like having to change motherboards and stuff b/c of the drivers, could be wrong though.