PC won't let me boot from CD
my old pc is cluttered with viruses, registry errors and general crap so ive decided to format it
however when i start my pc with the windows XP installer CD in, with my BIOS settings set to boot from my CDROM drive it comes up with "Press any key to boot from CD" but wont let me press any of the keys on my keyboard, it then goes to the screen which says windows did not shut down properly and again i cant use my keyboard
however, the keyboard works fine in the bios and in windows
any ideas of what i can do?