I'm faced with this very question myself. I just bought a new laptop, and it is on the way - my old laptop already has a new owner waiting for her. Still, I used to do a lot of crypto stuff with this laptop, and I'm afraid a regular drive wipe won't be enough to get rid of all my private key stuff that could give access to my crypto to someone else...

So other than doing a regular wipe, maybe 2 or 3, what would you do to guarantee that those keys are not recoverable? Or should I just surrender to my paranoia, buy a new drive, and take out the current one? I'm pretty sure people here have faced this very question here.

How would you protect your Bitcoin and alt-coins private keys from being taken over by someone attempting to recover data from your drive on purpose or accidentally?