What should I do about my data if I'm selling my computer?

Episode 1376 (11:15)

Jeff from Valley Village, CA
HDD

Jeff wants to do some spring cleaning by getting rid of some old computers, but is concerned about privacy and the data on the hard drives. Leo says that the easiest thing to do is to simply remove the hard drives. He could also use something like Darik's Boot and Nuke (DBAN) to completely wipe the drive. It erases everything by writing zeros across the drive, and then erases it again. If he does that several times, he'll be safe from everyone save the NSA. Solid State Drives, however, can be easier to get data off of. So he should take the SSDs out. If he's selling the computer, then he could replace the drive with a new one, or just sell it for about $50 less. Where should he sell them? Leo says eBay is best.

Also, for SSDs, when he gets a new one he can turn on encryption before doing anything.

Image By William Warby from London, England (Hard Drive) [CC BY 2.0], via Wikimedia Commons