Problem with Abit KR7a (non raid)

[minuteman]

My system setting is at the end of the message.
Problem:
Don't hear the POST beep when the system start, yet it starts up fine and able to install the OS fine.
OS running fine but will crash (reboot) when I try to install/run certain software or when I try to access .mpg/media files.
Any idea what I need to do?
Thank you.
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My system setting (not overclocking):
retail XP 1600+
Fong Kai fk320 case with 300W power supply
2 Mushkins 512mb High Perf PC2100 CL2 on DIMM slot 1 and 2(Bios setting cas 2, bank interleave 4, trp at 2T, tras at 5T, trcd at 2T)
Asus V-7700 Geforce 2GTs graphic card (AGP, with Bios setting 4x with Fast write)
Primary hdd: Maxtor/quantum 40gig 7200rpm
slave hdds: IBM deskstar 75gig 7200rpm, Maxtor 80gig 5400rpm
Plextor 12x burner
Pioneer 106s Dvd rom and maxtor 12gig hdd attached to Maxtor ultra ata/100 controller on PCI slot 3
NetGear FA311 Ethernet pci card (pci slot 4)
Philips Acoustic edge sound card (pci slot 2)
The USB expansion card that came with the motherboard on PCI slot 5
Running Windows 2000
Installed latest VIA 4in1 driver 4.37V
Installed latest USB filter driver
Installed PCI latency patch
Installed Service Pack 2

 

[AMD4SPEED]

Make sure you have a 350 or 400 watt power supply. I had a problem where my power supply wasn't pushin enough juice and my system would occasionaly crash if I did CPU intensive work. Swithced out the power supply with a beefier one and no crashes since. 1600XP is a high wattage consumer.

Just a thought.

 

[minuteman]

But my crash is fairly consistent, can be repeated when I want to open up media files (.mpg) or only when I try to install certain softwares, otherwise its stable (I can open up winamp and play mp3 files but if I use siren Xpress it crashes). I could open up media player just fine, but if as soon as I open up a media file it crashes. Could that be power supply problem? I am actually considering a new power supply, but I am not sure which one to get for my case since some of them don't fit in well.