thanks for the tips so far guys, but here is some more info...
ok when i first assembled my system everthing was working great, absolutly no problems ET would go vice city would go, but i got a little crazy on the instals so i dicided to do an xp reinstall. It was only after i partitioned my HD and installed XP again that the problems occured. My system is currently not overclocked at all, i think i got GAT in like turbo or something, mem timings are pretty lax, and my graphics card is not oced at all. I do have all the latest drivers and BIOS on here. What I can't figgure out is that a the games worked flawlessly when i first installed them higher res, high detail, and no problems, and its only after a day or two that the games died on me. ET in particular i could uninstall it, and reinstall the game and it would run fine once and then die as soon as the game is about to go 3d. On a side note, NHL 2004, and HALo run fine, no problems like i had with those other games...
Anyhow, i'll give ur suggestions a go and hopuflly i can figgure out what is goin on..
*edit*
memtest - no floppy (no memtest 86), but i did run sandra's memtest a while back and i think it was ok
scandisk - ok