Originally Posted by setishock
Cabbs is right.
Also look at that list of parts you have.
4gb fatality ram (2 sticks of 2gb)
GeForce GTS 450 << power hog
100 gb hd w/ windows 7 << modern drives don't pull that much
450 watt psu (smartpower) << not enough
xtreme gamer sound card << power hog
ASUS P5B motherboard
Now here's my take on that.
1. The power supply is not able to push all that and a higher end cpu. It's going in to over draw protection.
2. There's a short in the wiring and it's going in to short circuit protection.
3. The old cpu was over clocked from the bios and the bios was not defaulted before installing the new cpu. Put the old chip back in and default the bios. Make sure you have a pasted heatsink on either of the cpu's before you try to fire it up.
4. While you have the old cpu in update the bios.
1. Both have TDP of 65W, but in reality, 45nm draws less power
2. possible, but extremely unlikely
3. A simple CMOS reset should be enough, but even that shouldn't be needed. When a new CPU is put in, Asus boards don't have a problem, they just say "new CPU found, change settings in BIOS"
4. YES! This is the most likely. Either your board has a BIOS that does not support newer 45nm architectures, or it does not support them at all