windows vista/xp

i am resubmitting because i did not recieve a reply in over about 24 hours while those who have put up threads after me have received replies, my post is-
"i bought an acer aspire 5100 a while back, it came with vista.
its been like 6 months or so since i got it and i decided to install xp on a seperate partition. it all worked fine, i got all the drivers and all, there's only a slight problem. when i choose to boot the computer to xp, as soon as i choose xp from that moment on, the computer can suddenly shut off at any moment, whether 2 seconds later or 30 minutes later... i cant seem to find a solution.
my specs are-
processor- amd turion 64x2 (dual core) mobile technology 1.6 ghz.
graphics- integrated radeon xpress 1100 series
HDD- 160 GB (i think its SATA) << could this problem be occuring due to the fact that my hard drive is a serial ATA one?
ram- 2 gig ddr2

i hope someone can help ... thanks in advance "

can i please get a reply this time...