Off topic? need help with computer instability

[jasonfinal]

Thanks for everyone's help, I bought a Pioneer-A04 (lots cheaper than the A05). But I'm plagued by computer problems and can't burn anything yet since my system is totally unstable.

This is somewhat off topic and I apoligize, but out of desperation I thought I might try this forum for some help. Read on if you're interested...

Pls suggest what you think may be the problem. BTW, I've tried just about all the lastest drivers and bios.

In Win98, internet explorer continually comes across an error and closes the page.
In WinMe, similar problem with internet explorer and usually freezes when downloading from newsgroups, can't run 3dmark test
In WinXP pro, can't run 3d applications. (Infinite loop?) At worse, it reboots even when I'm not running 3d app.

My system:
Abit KG7-raid
Amd Athlon 1600+
Audigy Live platinum
Quantum 40gb 5400rpm HDD & WD 20g 5400rpm
Hynix DDR ram pc2100
Prolink GF2ti & Asus 8170Magic (GF4 MX440-se)

I've mixed and matched with the HDD and vidoe cards, and problems are still there.

Any help appreciated
Jason