I am trying to reinstall Windows XP on a HP ze4560us laptop. The computer was badly corrupted with a virus. I have reformatted the hard drive and flashed the BIOS. Now when I do to reinstall the Windows XP operating system disk, I am unable to type in the product code. The keyboard lets me type letters but it doesn't let me type numbers. It gives me symbols instead of the numbers. Can anyone help? I am about to throw the computer out the window.