Back up all your info (put it on a disc (program files cannot be copied correctly because they rely on dlls and registy entries)) Buy the Windows 2k cd, if you can find one! KEEP THE BOX YOU WILL NEED THE KEY ON IT. Put the disc in and restart your computer. On the first screen that comes up (usually displaying your manufactuer's logo) the bottom should say something like "Press F2 to boot BIOS setup - Press F7 for boot devices" Go to boot devices (different from different kinds of BIOS') and boot from disk. Follow the on-screen instructions from there. One thing to remember is that you want to wipe your hardrive, not install on a new partition, it will ask you this.