From: rbchinchen on
I have installed and run Ubuntu on a dell dimention 2100 series with
no issues. this is a p4 2.26ghz with 256 mb ram, onboard intel mobo-
integrated graphics, 38gb hdd, so basically same as yours. i would
suggest it's not a spec issue but probably hardware. try running
memtest to see if you have a ram issue, if not check the hdd for
errors.

if you still can't find the issue, crack open the case and check for
any capacitors on the mobo. if you have some that have a blown or
bulging top they can be causing almost any issue. i had this once
myself, really hard to diagnose with software, but takes 3 seconds to
check the hardware.
From: rbchinchen on
og, and btw, when a live cd initialises it loads into the ram, so that
again points to the ram as the culprit. leave memtest to do at lease 5
consecutive full-passes.