Old hardrive

i found an old hardrive from my first set up and i  want to use it in my current setup the problem is it has windows installed on it and i was wondering how do i wipe the drive so its empty?

you format it


okay yeah but wont it cause a problem with my current setup? since i will have a different copy of windows with a different key code on there?

You can always use the way of stealing software........ windows is kinda ok with it cause they think if you steal it now you will buy it later or buy word or something

http://www.dban.org/download this is a great HDD formatter