The last thing I suspected was the keyboard.
Built a system. Powered up, went into CMOS to set date, time, etc. Finished, did save settings and exit. System rebooted and then went back into the setup page. Saved and rebooted, did it again. WTF?
Turned off power, waited 30 seconds, power on and nada-no fans, no lights-dead.
Check everything, swap the usual suspects-memory, video card, P.S.-nada
Clear CMOS and turn on power-it works, get back to CMOS setup to settings, save settings and exit.
Rinse and repeat.
OK, take everything apart and swap motherboards, hook up everything including drives and install windows-everything goes just fine until get to desktop.
Takes forever to do anything. A 4.2 GHz quadcore and 120 Gb SSD shouldn't take that long to react.
Finally remove PS2 keyboard and plug in USB keyboard.
ZOOM!!!