text: i just bought a newer used desktop pc.  would you suggest i have it reformatted by a pro and why?   to answer your first question about having it reformatted. i think that you should definitely reformat it. you don't know how well the other person took care of it, therefore it could be infected with spy-ware and viruses, which will affect the performance of the computer, and some of these will collect information from your computer.  i am assuming that you already have an operating system (windows 2000, xp)  you do not need a pro to do this. it is really simple. when you turn on the computer, just insert the cd into the cd-rom and you will see on the screen a message that says...  press any key to boot from cd...  at the following link you will find the steps on how to do that  http://www.webtree.ca/windowsxp/clean_install.htm