New Computer Wont Post

[giantpinkbunnyhead]

My brother ordered some new parts for an old computer and he's having problems getting it to post. I looked at it and am equally puzzled. It's a new mobo, (I don't know which brand but it's a cheapo one, An AMD 3800X2 processor, and 1GB of RAM. This is an AM2 setup. He's used the existing power supply which is only 250W. There is no GPU but the mobo has onboard video. The existing hard drive is hooked up via SATA cable, and the only other peripheral is a CD drive. The hard drive, I'm sure, is a generic SATA drive. Nothing fancy.

When he first fired it up, it worked OK; then he decided to reformat and re-install windows. now the computer freezes on the first startup screen, where it states what kind of processor is present and asks us to hit DEL for setup; and F11 for boot menu. It will freeze right here; we cannot open either menu. Can't get into the BIOS or anything.

Any generic ideas that could cause this, or perhaps did my brother get a bad part(s)? It's odd because initially it worked almost perfect. I don't know why he wanted to reformat but anyway... this is the current problem. Any help is appreciated.

edit: tried removing and reinstalling the lithium battery.
tried clearing the CMOS using the jumper on the motherboard.
tried with and without a CD in the CD drive.

edit 2: OS is Windows XP Pro.

edit 3: Tried swapping hard drives; no change whatsoever.

 

[Job]

Swapping out HDD with other windows set ups has caused me problems before - did u try just re-installing XP again? When the PC tries to post does it

1) Do a quick mem test?
2) Show a list of different hard drives?

If its not showing a list of HDD its likely not recognising them or having problems accessing them. Try booting into the HDD drive in question from another PC. Try using a different SATA port. Try unplugging all the components and take the plug out of the back of the tower and leave it for long enough for all the current to leave the system (20 mins or so). Can't really be more specific im afraid!!!