Simple, put it in a box and use it.
I've been doing this for years. You see, for years I've been recycling computers by going through them and setting them back up and passing on to someone who needs them. Sometimes I hear of a story of someone tossing their old machines and keeping the hard drive in a closet.
Because it's safe.
No, not really. You see data is "forever". I've dropped memory sticks in the pool and after drying them off (and out thoroughly) they work. Sometimes. Sometimes not.
But that old hard drive on a shelf? You can still read the data.
So today I was going through the normal morning digital chaff and found a deal for an external drive case. It's a little metal box into which you plug your old hard drive. Once you assemble the stuff (two screws typically for a laptop, a few more for a desktop drive) you can plug that drive into your new computer and get the data off of it or run a program to "securely delete" the data.
Oh sure, the government and some police agencies know how to recover some of that but for the most part, the yahoo that ends up with that drive next won't know how.
Here is one article from an old ZDNet posting from 2007 that goes into all that secure delete deeper. If you're really curious and don't want to fiddle around with weird command line stuff, there are other programs that will do a "Secure Delete", just search your favorite search engine for the term.
The deal is that you now have what is in essence a big fat floppy drive that runs really fast. What you do with it then is up to you, but if you've gone through and formatted the drive, and have an empty drive, you can treat it as a place to store a copy of your "most important data".
You know, things like tax records, receipts, recipes, pictures of the dog, a copy of the check you sent to me because I'm such a good guy... that kind of stuff.
Only kidding about that dog thing.
The deal is that the hard drive in your desktop machine is about the size of a paperback book. A thick one, but a paperback book. The hard drive in your laptop is even smaller, thinner than a cigarette pack and probably about 1/4 as thick. You can store these things with data in them for years in a secure place like a safe deposit box or inside grandma's mattress and not worry about all of that stuff getting lost or someone getting hold of it by trash picking it out of your bins.
Don't throw out electronics if you can, after all it will just pollute, but you do get the idea.
What got me thinking was that I have a stack of old laptop drives in the back room, all 40GB or larger. A memory stick of 32GB is around $32, the case cost me $4 each and I have the drives. May as well use them.
Just make sure that when you pull the cables off the old drives you look at the connectors. Pins mean IDE, Slot connectors (typically grey) mean SATA. Buy the right type and it's pretty foolproof.
You'll sleep better knowing that there isn't some wierdo looking over your old data.