Simple
●Buy a new hard drive
●remove the old one
●insert the new one
●install XP
●reinstall all your old programs
●plug the old hard drive in as a secondary hard drive.
Now for the complicated part:
If your computer's existing hard drive is connected to a flat ribbon-like cable that's 2 or 3 inches wide and thin like cardboard, it's an old ATA hard drive. Buy a new ATA hard drive, NOT an "SATA"! Also inside your computer see if that same ribbon cable has an extra connector in the middle that's not plugged into anything. If it is, that's what you plug the old hard drive into at the very end. Make sure you find the jumper on the back of both hard drives (the little plastic thingie on the pins in the back) and move it to CS for Cable Select on both. If there is only one connector on the cable other than the one plugged into the motherboard, you need to get a new one. You should be able to find one where you get the new hard drive.
If however your hard drive is connected by a cable that's only alittle wider and flatter than your ethernet (/network/internet) cable, it's an SATA cable. In which case make sure you get an SATA hard drive (the most common) and check if it comes with a cable (sometimes they don't) Just use the cable already in your computer, then before you're done, connect the new cable to your old hard drive and your computer (in a new slot).
