When we sell our laptop or desktop to trade shop, what is the most important thing we should do before hand over to the shop? It will be clearing off our personal files. But by using normal function supplied by the system, it does not really 100% remove them and it can be recover by some software. This means we need some sort of hard drive wipe that permanently erase all the files.
Personal data are important and valuables to us and maybe to others if your hard drive do contain other person personal information. With this safety applied, it will prevent crimes happen. So, make sure you get a tool that permanently erases all the data before selling it.