I had the same problem. After a lot of ridiculous discussions with helpdesk people who kept on suggesting that I look on the internet for a new boot disk (not understanding that I couldn't run the disk because even at the BIOS stage the computer keyboard is frozen), I spoke to a very helpful man who told me that it was down to some static problem.
The solution, which worked for me, was to remove the battery and hold down the power on button for about six seconds (you must ensure that the computer is not plugged into the mains otherwise it will just switch on). This apparently resets some internal switch and your keyboard should then work. Hope this helps - it is very annoying when it happens and you can't work out how to resolve it....
Patrick, February 2007
