Problematic HW?!; failed load xp;

Hello,
few days ago I started to get blue screens in XP. I can't recall what I did exactly before but what I do know is that I didm manage to login to xp but after few seconds I got blue screen. The next thing was try to startup in safe mode and make restore system. but duing the restore my pc hung up which end up with pressing the RED button. From that point few times the pc shows the XP introduction window then reset, few times it got reset even before.

the next thing I did is to place FINE HD from another PC which has double boot of xp & Ubuntu and disconnect the old one. on startup I managed to get into GNU GRUP window (to select xp or linux).
from here, 4 times out of 4 the windows failed to load and got stuck during initialization with blue screen and reset. 1 times our of 4 the linux got failed to load and got stuck (for the 3 times it suceeded loading linux, it worked fine with no problems).

The next thing I did is to make default configuration to all BIOS. Yet it didn't help from xp.

To me it smell like HW problem as I isolated the software.
help will be appreciated.


CPU: PENTIUM D.CORE E2200
MBOARD: BLKDG31PR
HD: 250GB 16MB SATA2 SEAGATE
VIDEO CARD: GF8400GS 512MB PCIE
MEMORY: 1G DDR2 800MHZ KINGSTON