1. Obtain a genuine XP installation disk with a genuine key.
2. Obtain all drivers for your hardware. Your m/b manufacturer may, or may not, produce XP drivers.
3. Set the BIOS to boot from the CD/DVD drive.
4. Place CD in drive.
5. Boot the PC and follow the on-screen instructions.
6. Use Windows Update to immediately apply all security updates.
7. Enjoy your obsolete, inferior Operating System. (Support for it will cease in 3 years time.)