Windows XP won't load

[xyvian]

Alright, so i've browsed around and looked at the other people with similar problems, but mine seems to be something completely new.

a friend of mine got the update for internet explorer 7, installed it, disliked it and tried to uninstall. it gave him an error and he had to restart his computer. everything was loading fine until he got to the windows loading screen. after about 3 seconds it restarted. it does this cycle even now.

I tried as much as i could to save it, but decided to reformat windows. even with a fresh copy it persists. I even put in a working hard drive (the one I am using even now) and it would not load still. So I thought powersupply, but to no avail. tried is video card. same effect. replaced memory. nothing.

finally replaced his mobo, and the loading screen lasts a second longer. replaced his cpu.....

the one thing that i realize now that I didn't see before, since he was the one to replace it, was that he is using, and always has been using, a 20 pin PSU while the mobo requires 24 pins. is that, with 100% certainty, the problem? I don't have a spare to test and he's not keen on spending more money... he had been using the PSU and mobo for a good year and a half with no problems.

any help is appreciated.

[gerbil]

IE7 is capable of many foul things... but it doesn't often remove PSU pins....
Anyway.. "reformat windows"... d'yu mean you formatted the system volume [partition] and reinstalled windows? Then you replaced the mobo and CPU, [so i guess the first reinstallation is a tad irrelevant here... :)] the HD, vid card and RAM...??!! there is only the NIC, burner and case left! Everyone has a burner...

[xyvian]

by "reformat windows" i mean i formatted the system volume and reinstalled windows. NIC is onboard, burner has been unhooked for a while.....

so, about the PSU?

[gerbil]

if it worked once, then the number of pins in the PSU plug should not be important. But their placement in the mobo socket will be. So i'd go on google with mobo make/model and psu model and get info, diagrams.... the latch/alignment mechanisms may not force necessarily the correct alignment.