selling my laptop, how to clean everything off?
I'm selling my laptop and want to clean everything off so it cant be traced or hacked or whatever people can do to it. I've backed up all my files, and am about to restore the laptop to the factory settings. Anything else I should do before restoring to factory settings? Do I need some type of hard drive eraser that makes all files unrecoverable? If so which one and do I use it before or after restoring my laptop?