whats your previous OS? if you have that CD, then pop in the cd, and instal, and restart, if it is easy. if it is previous version of windows, just pop in the cd, and let it take over. it will install some files, restart your computer, and when it asks, press any key to boot from cd, then hit a key, then let it roll. make sure you format your harddrive before you install your other OS. the OS you are trying to put might ask if you want to format or not!