I have an older Lenovo ThinkPad that I got from a previous employer in 2008 that I need to sell quickly. It runs XP Professional and I never got copies of the setup disk. I need to wipe all my personal data before selling it, but I can't figure out the best way to do that and keep the OS intact. Even though no one really wants XP Pro anymore, I assume that selling it with the OS completely wiped will limit the number of people willing to buy it. I was hoping to just do a clean install of XP, but without the disk it's damn near impossible. I tried reinstalling XP from the WINNT32.exe file, but its telling me the product key (found on a sticker on the back) is invalid. I've looked at a couple of programs for wiping data, but I haven't found anything that can guarantee that my OS remains intact while all my personal junk gets zapped. Also, if I could find something free, that would be better since I'm broke. Please tell me I'm missing an easy solution. I need to sell this thing in the next 48 hours if possible.