I've installed a new P4 3.2ghz CPU in an ASUS P4P800S-X Motherboard. Origionally there was a celeron 2.0. Now when the computer starts it says, intel cpu ucode loading error. press F1 to continue. When I go into the bios it detects the CPU correctly. I've updated the bios, cleared the CMOS a number of times, tried to slightly overclock it but it still gives the same error. when I push F1 it starts fine and runs good. It also has a new CPU fan designed for a P4 3.4ghz but I noticed it's running a little hot, 66 degrees Celsisus. Could that be the problem? I'm all out of ideas and I've done everything else I've found on the tech sites.

Also now when I put the old CPU back in an error comes up saying the cmos is incorrect and gives the option to go into the bios. when I make sure everything is fine and reboot the same error comes up. when I put the P4 back in I get the above problem with the ucode loading error.

prior to putting in the new cpu the board and system worked fine.

I have the same problem with you when I try to install a P4 3.0E(3.0/1M/800).I have also receive the message Intel CPU ucode loading error.
Update your BIOS version to 1011 will solve the problem.
If not, you really have faulty mobo or CPU.
Goodluck!

ASUS P4P800SE
P4 3.0/1M/800
1GB Kingston HyperX DDR434
ASUS 9280 S2 GF4Ti AGP8x
AcBel 450Watt
Maxtor 160GBx2 Raid 0
SoundBlaster Audigy

Yes I already updated the bios to 1011. I suspect the cpu as the old cpu did work fine untill all this happened.

Just to let you know, I purchased a new CPU and got the same problem. the only thing I can figure out is that it's the MB. It recognized the old celeron just fine until the bios update..... oh well, one of those "I can't explain the problem" problems.