did you try running command.com using moslo - IE
start->run->moslo /20 command.com ?
Thats the most reliable method of activating it. Although if you do that it slows down everything until you exit the DOS box (As I found out the hard way
). If that dont work, youll probly have to underclock your CPU to 650 (Never, EVER, trust it to run at the exact specification). I dunno much about altering clock speed on p4/athlonXP class chips, but a PIII or Athlon class can be dont through the BIOS.