Windows 7 ultimate fresh install keyboard doesn't work

Hello,
I have a Compaq f500 that was running Vista home premium. I did a fresh install of Windows 7 ultimate. It went thru the install with no problems. When it got to the screen when you put in your name I discovered that the keyboard doesnt work. I tried plugging in an external keyboard and it doesn't work either. Also cant select safemode or anything that requires use of the keyboard to enter.