Well try getting another power suppply. Just take your system into a local store if you dont have an extra one and test and see what happens.
Or it could be nothing to do with the bad weather. Could be a virus even.
Anyways what I would do is take out everything but memory, grahpics card, and hard drive and see what happens. No mouse, no keyboard nothing. Might need to turn of error control in the bios so you can boot without a keyboard.
If still slow then switch memory, still switch grahpics card and still switch hard drive. Still, switch all of them including power supply. Local store should let you test. Mine always does. They will even help out if they can for free. hehe
Though you already did a stress test so guess bad power suppply.
Also, have you tried reloaded the bios itself? I mean reflash the bios not just load defualt settings.
Process could be stuck running in a lower mode too. Try taking out the batery on the motherboard so it resets the cmos. Or you can use this program if you have cable bios system:
http://www.cgsecurity.org/cmosbackup-1.1.zip
I used it yesterday because my mother board caused the bios to lock up and set an unknow pw so I could not even boot. This app reset the cmos and got rid of the pw. THough you do have to set the time again which is not a big deal.
Also if it is a virus simply reformating your hard drive does not always mean getting rid of it.
You first backup your hard drive. Then you delete all the parirtiions off the hard drive. Complete delete them. Winxp setup will recreate it for you. Then write zeros to the entire drive. This will take hours. But will ensure no more virus. You can normally get the tool from you hard drive makes website such as western digital's support web site.
Then you reset your bios and cmos using program above or taking out battery on mother board. Then you finally install winxp again and let it recreate the paritions and then you install windows. And hopefully everything will be great.
Also in the bios it does report the correct speed of your processor right? And correct fsb? That is front side bus. A lot of mother board reset to 100mhz so make sure its set on correct fsb for your processor.
Hybrid Mode
