computer restarting

I am going over later today to fix a computer for a friend. Don't know the specs right now but I belive there something like this.

500 mhz celly ?
64-128 mb ram?
10 gig hd ?
Cdrw drive
vidcard ?


Any way the proplem is the computer was resarting all the time when they used it. Now it can't go more then 4-6 minuntes with out the computer restarting? Whats bad on it? Would an older celly restart if it got to hot? Or is the cpu or the mobo shot?

Any help would be nice.
Thanks,

the problem is with a machine that old it could be a number of things...the PS could be going bad...chip could be on its last leg....mobo could be going out....

check the PCI cards...remove all of them and replace them one by one to see if one of those are causing a problem...

if all else fells tell them you will build one for them

BAd drivers or something u installing and Windows does not like it can cause the problem...i would re-format there machine with a fresh install of Windows....and if it keeps happening (do not install anything yet) then it will be a hardware problem...

Try and make sure that the fans are working in side the machine....make sure all the vents are clear so air can get in and out...might be the computer is over heating...

Its not the power supply I just put a new one in it a while back for them.