While installing Windows XP on an old notebook of mine, on every try - i would error on random files that couldn't copy over. So, I suspected bad RAM...

Ran memtest86+, and it racked up errors like crazy, 100,000+, and eventually crashed with loud beeping flashing different colors with the character "a" printed all over the screen. I figured the entire ram module was just totally bad and dead..

so finally today I go out and buy a new stick, same specs,
try to install XP again, this time i get a bsod stop error somewhere in it saying something about ACPI or something.. i didn't catch it and haven't been able to recreate the error..

none the less just to check i ran memtest again, and i start racking up errors from the start, already at 10,000 by 80mb.

what could be the problem? i tried both slots.

edit:
a little info about the notebook: got it for free from someone, old/broked. i wanted to fix it. it says its an Alienware, i don't know what model exactly, i think it's manufactured by someone else though. it's some generic Notebook D500P/510/530 model A. i don't know what that means or remember how i found any of that out. i don't know much about the machine but i figure this problem is irrelevant.

it's a p4 @ 2.6 mhz, and both the old and current ram modules are kingston, 512MB ddr @ 333mhz

edit2:
the error on xp setup was PAGE_FAULT_IN_NONPAGED_AREA

you could have a bad ram slot or the mobo is shot. Also check your CMOS battery. You may require professional replacement.

How do i check my CMOS battery?

1st of all, tell the exact model of your laptop

it requires opening up the system and replacing it. I don't recommend this for laptops. Take it to a professional.