revert back to old OS ( win.2000)

I installed windows xp to discover the hype of the new great windows system, but discovered it was terribly sluggish with my 64 MB of ram, so i want to go back and reinstall windows 2000 Pro. But it wont let me install it, saying the setup file which im trying to run is for an older operating system and therefor the setup will be disabled. What do I do? Thanks

 

What u should do is 2 steps. 1) backup all your personal data from the hard drive like files.doc and others 2) install the WinXP as a fresh instalation and chose to format the disk.
If u have at least 6 GB of hard disk u should devide it to 2 partions, c: and D:, on drive d u should put all your personal things and in this case whenever u r installing a new version like Windows 2000 or XP u can install a new freash copy. I hope u r installing Win2000 from a boot CD.