Sadly, that would be a naive assumption. The truth is, it's very difficult to permanently get rid of your data. And if you want to do so, you probably need to go get a drill.
That's the advice of the Geek Squad's Matos, who said that, "When you delete [data], yes, [its] icon may be gone, but that information is still intact on the hard drive. The only thing the computer does is [mark] that section to be overwritten. It just gives the operating system the OK to write over that area."
So if the operating system isn't actually removing the data from your hard drive, how can you get rid of it?
Matos said it's not so easy, and you may not ever want to just hand an old computer off to someone else if you're worried about them accessing your private data.
The only way to ensure that no one can ever access it is to bring tools to bear. "Let's say you're getting rid of an old computer," Matos said. "You're going to want to take the old hard drive, take a drill, and drill 10 to 12 holes through the drive--and not in a straight line. Scatter the holes and make sure they go straight through.". You can also access this blog from TechSoft Solutions homepage.