If you wipe everything, you have nothing left, not even Windows. That's only a good idea if you have recovery discs or can boot from a recovery partition. If you don't have those, it means a partial wipe, and that's quite something else. So please tell more about the situation.
I'm upgrading my notebook so I plan to sell my old one. How would I permanently wipe the system so nothing can be recovered such as work information, passwords, pictures etc. It's running on Windows 7