I have a ECS A790GXM-A (no tweaks) and and AMD 940 Black Edition processor. I had the original BIOS and just updated it to the latest version. Both show in device manager as AMD and processor type unknown. I just tried the chip in a ASUS motherboard (ASUS M3A78-T) same AMD 790 chipset and loaded the drivers from the ASUS cd and the processor shows up correctly and runs a awful lot faster than the ECS board. Anyone experianced this? Is there a problem with the board?

It's recommended to update the BIOS then install Windows (not the other way around)
Obviously confirm all system drivers are up to date
Or do a Repair on Windows

Microsoft's Windows XP Professional Repair Install step by step
http://www.windowsxpprofessional.windowsreinstall.com/installxpcdrepair/part3.htm

Microsoft's Windows XP Home Repair Install step by step
http://www.windowsxphome.windowsreinstall.com/installxpcdrepair/part3.htm

Vista Repair:
http://www.windowsreinstall.com/winvista/index.htm (index page)
http://vistahomepremium.windowsreinstall.com/repairstartup/repairstartup.htm (guide)

This is why posting more info helps

For further help: Please put your System Specs information in your Profile

TY for the reply

FYI----ECS just released an updated BIOS for the AM3 chipset, for this motherboard, this might also fix my issue as well.