New assembled system wont start WinXP...

[Kayote]

I built a new system after getting new components. System specs are:

AMD Athlon 64 2800+ (new component)
EPoX 8KDA3J (new component)
512MB DDR 4300 TwinMOS RAM (new component)
Q-Tec 450 PSU
40GB HDD (from old system)
Radeon 9600 PRO (from old system)
SB Live Value 5.1 (from old system)

The problem

The problem is that when I bootup my PC, when it comes to loading WINXP, I just get blank black screen for a few seconds and then the system restarts.

Ideas tried

As the RAM is not supported (the motherboard only supports upto DDR 4000, I am suppose to overclock my system to get it to work, I think) I replaced the RAM with my old sytem RAM (Crucial 256MB 2700). Its still giving the same error. Do I take it the RAM is not at fault here?

As far as Im concerned I never had any bad sectors in my HDD. Could it have suddenly failed? I did notice, when it restarts and gives the message of windows not shut down porperly the last time, I selected 'safe mode' and it went upto mup.exe file and then stalled again...

Could there be anything else Im missing.

PLEASE HELPPP!

 

[mechBgon]

If you're trying to re-use an existing WinXP installation, generally it's not going to just adopt a brand-new mobo unless it's similar to the previous mobo. Start with a fresh install and don't catch worms either.