Need Diagnosis on MAJOR PC Problem

I'm running a adequate Pentium D @ 2.66 machine with 1 gig of RAM, 256 meg decent video card and about 320 gigs on 2 hard drives (300+20).

It's been working fine for about 1-2 years, but all of a sudden it's taking REALLY long to unrar files, move stuff along my various partitions and burning DVD's. What use to take about 30-45 seconds to unrar a a DVD ISO now takes 15+ minutes and over 1 hour to move/copy data across partitions on the same hard drive. Even burning a full data DVD takes approximately an hour,  about 54 minutes more than what it took a few days ago.

I haven't installed any new programs, in fact I've been uninstalling apps I rarely use and burning most stuff to DVDR prior to all of this. I run weekly spyware and virus checks and nothing's ever come up.

I have a few theories as to what's about to die.

I'm guessing it's either....

- the primary HDD (20 gigger one) that hours my XP SP2 OS
- the slave HDD (300 gig) that stores my music, games, movies, prawn
- RAM (reason why everything is now taking forever
- mobo or CPU - kinda doubt it, but who knows

Anyone know any sure-fire programs that tell me whether or not my HDD or RAM is dying or failing? I have receipts for my HDD's and would like to replace them before the warrantees run out if that's the problem.

Halp 4chan - any useful input would be greatly appreciated. Thanks.

try booting off a live CD.  if your problems persist, it's hardware-related.  if not, it's software-related.

if it's hardware, my guess would be RAM.  very possibly the IDE controller (read: mobo) or hard drives, but problems in those would likely cause significant data corruption/crashing as well as slowdowns.  back up your important shit NOW just to be safe.