How do you install Windows XP?

You have to have distributuve of Xp (installation files). If you have OEM or Retail Cd just backup all your information from the hard where you want to install to. Then boot from the CD and follow instructions. You might need format and/or create new partions. If you have just installation files then you will need bootable MS-DOS disk (your files should on the disk with fat16/32 system).