strange slowness that i cannot diagnose

Ok, I may have to re-edit this problem in a more specific details oriented type of way... but, for starters I thought maybe I could give the general symptoms....
So, I went to work one day, came home and my computer was froze. I rebooted and it came back into windows (xp sp3) but seemed to be very slow... I noticed however, before i rebooted that the norton security that comes free with my comcast internet had said that my subscription ran out, which led me to believe maybe a virus might have snuck in while i was away... the norton subscription should not have ever ran out to start... (so, that is odd)
anyhow, when i rebooted things inside of windows became very slow... I thought maybe it was because something got in, but now im not so sure. I wonder if perhaps my HDD has an issue. I tried repartitioning my main C: drive, and leaving the D: drive how it was - then installing a fresh copy of Windows XP sp3... However, when attempting to re-install Windows - it crawled at a remarkably slow pace in relation to previous fresh install.... So slow in fact that I got tired of waiting and went back on my old computer.

I searched for answers on google to slow xp installation and saw posts about, "make sure your cpu is not set to compatibilty mode...." and even one that said: "oh, slow xp install, I have had this before - remove mobo battery for 30 secs, reboot try again...." :\
Obviousy none of that helped, and I didnt even see a compatibility mode option in the BIOS settings for my CPU...

My pc specs are as follows (to be updated more specifically if I really must):

CPU: Phenom II X6 Black Edition 1090T Thuban 3.2GHz 4000MHz Socket AM3
CPU fan: stock fan that came with the CPU
Mobo: ASUS M4A89GTD PRO/USB3
Ram: ordered - A-DATA Gaming Series 4GB DIMM-AX3U1600GB2G9-AG (two 2gb sticks) on sticks, says "AX3U1600GB2G9-2G") i dont think prob is RAM related....
PS: Galaxis LX Series 600W
HDD: Western Digital Caviar HD-WD5000AAKX Blue 3.5in 500GB SATA (6)
Case: Nothing fancy, case from Directron.com, standard ATX....

So far, I have only tried repartitioning the C: drive, and leaving the other half the D: drive (of single HDD split partition) intact... Could it be that the D: partition is infected and causing problems with slow re-installation of windows on C:? Or, could it be that I may have damaged CPU by using the mobo's software over-clocking utility? I figure, not really knowing for sure, that if the CPU was bad, or the mobo or the ram, then it would not even POST... so... I wonder if perhaps the HDD became faulty somehow, and it is the component that is bottle-necking everything else... perhaps do to bad sectors or a virus....
I have no spare components to test any of the individual components as this system is a light year past my old one. But would love any advice/suggestions that I might try, short of RMA'ing anything b4 warranties expire.

 

It of course could be RAM, run memtest86 and for your hard drive go to the makers site and download their tools and use the 'bring back to factory condition' option which will erase everything on there. If it's still the same then I'd replace the hard drive cable(rare occurence) and if that doesn't work then it's your mobo.

BTW, after all that verbiage above I remembered that you OC your machine, bring the BIOS back to default first as your RAM could be being pushed too hard. That's all I got.

 

Thanks for you advice. I already made sure that the mobo was reset to defaults. Gonna try swapping the cable, which I hadn't really thought of. If that doesn't work, I will concentrate on using the diagnostic tools and totally wiping HDD. I am definitely sick of putting off fixing the issue. It had just been less easier to get to the bottom of the problem than I expected, which has caused me to set it all aside and go back to my old computer for much too long now.