What are the recommended steps to take before getting rid of a computer by either giving it away or throwing it away? Is using Darik's Boot and Nuke (DBAN) enough?
Sometimes license stickers are glued in computer cases (Like windows). If you have these licenses related to you somehow in other integrated systems, it's a good idea to remove them.
This may be a strange advice, but check if you didn't leave any removable media (cd, dvd, sd card) that could have personal/important files.
Since I don't have NASA files in my machine, DBAN is a good choice. :) If you're REALLY paranoid about data and don't know what people would do to your machine, make them sign a responsibility paper that you gave away a complete formatted drive, so if they find "suspicious files" in your HD, you're safe.
Backup or image the system first. There's always going to be the person coming back to you saying they need something that was on the drive.
Dban works more than well enough - that or Secure-erase. There shouldn't be any software way to recover any data. Unless you are worried about a major corporation or government coming after you, it is enough.
Check inside the case. In one former company, we used to put information on the inside of the case - stuff like IP address, repair history... Nothing major, but it was a convenient way of keeping history with the machine.
I'd say before wiping it or anything, make sure you can't salvage any of the parts first. U can always turn an old computer into a headless server, or a home theater PC, or something. I mean you'll most likely need to give it some upgrades, but it doesn't need to get thrown away.
If you're getting rid of it though Dban