How to Erase your Hard Drive

One Common question i get is this

William I what to sell my computer to my friend, but i do/did my banking on that computer. How do i Make sure that no matter how hard he tries he can never get it?

Short answer is change the hard drive. If that is not a possible solution, which is common, use a program called eraser (http://www.heidi.ie/eraser/), this program has a feature called create nuck boot disk, make sure your old computer has a floppy disk drive. The boot disk will overwrite your old hard drive with random numbers so it will be very extremely hard to recover the old data. you can also use eraser to make sure that just the data you want to erase is only erased but not a secure. there are blogs on more extreme way to protect your data but if your friend is trying to get your information that you need to resort to that level of extremes than well do not sell him the computer .