Frequent Computer Crash

Question

Got a PC with mercury motherboard PVM900, Intel D processor 3.0, 512 MB ram running on Windows XP pack 2. The problem is after re installing the XP i auto ran the tmotherboard cd and the VGA drivers didnt install i then checked with VIAarena.com for the drivers downloads for XP got them but never worked on XP pack 2 but suprisingly after installing XP Pack 1 the VGA drivers installed but no Sound i then reverted to XP pack 2 and sound came back and no VGA. I GOT THIS SNAPSHOTS A DAY BEFORE THE MACHINE REFUSED TO BOOT UP. NOW ON BOOTING THE MACHINES SHOWS THE WINXP WINDOW BUT NEVER BOOTS UP JUST A SILVER SCREEN . PLEASE HELP ME OUT OF THIS MESS.