xp keeps restarting but 98 works fine

System Configuration
P3 866Mhz,
256 MB SDRAM
Intel 810e (or 815) Chipset
40GB Hard Disk
1 Samsung CDROM drive - 52X
1 combo drive(cd writer + DVD)

Till recently I was running Windows 98 SE plus Windows XP Professional.
Recently I needed to install Linux on my system so I removed all partions from my 40GB hard disk and created new partitions for windows leaving around 6GB unformatted for Linux.
After formatting the windows partitions, I installed XP Prof. from the bootable cd.
Next I installed Mandrake Linux 9 on the system.
Things worked fine for a day or so after which Windows started hanging and restarting unexpectedly and with increasing frequency.
Amazingly, this restarting problem occurred in Linux too..
Doubting the installation, I repartitioned, reformatted, reinstalled XP from various installation cds but to no avail. The restarting problem still exists.
Now I have installed Windows 98 SE where there is NO problem of restarting.
Again, if I try to install XP as an upgrade to 98, either the setup itself hangs/restarts or if I am able to complete the setup ,XP continues to restart and hang randomly..

I think I have checked the RAM to be in place and not loose.
Besides, the CPU fan has been unmounted and cleant of all dust..
But this has not helped the situation.

Incidentally, I discovered, that the grounding of the PC plug point was not working properly and I was getting current on various parts of the CPU cabinet.
Though I’ve got this fixed now, could this be related to the trouble??
Besides, now-a days, the computer takes an exceptionally long time to boot(esp. at ‘Detecting IDE drives’ or takes a lot of time for the customary beep and the first screen.) Also, it restarts sometimes after the first screen of the boot up sequence..

What could the problem be??
PLEASE HELP!!

 

Any chance of substituting another power supply?

It's possible Win98 is starting ok, just due to putting less of a load on the PSU -- although I would expect that to be true of linux as well...

You might have had some damage there due to the bad grounding or excess current drawn.

And you certainly could have damaged motherboard components as well -- have a look for swollen, charred or leaking capacitors for one ....

I really think this may belong in the Hardware forum, as I probably won't have much else to say. If you want me to move it, just say so.