What Could Be Hidden On Your Old Computer?

We've all heard warnings about protecting your private information. But throwing away your computer can be as risky as throwing away your wallet with all your credit cards and personal ID inside. That's because data could still be on your hard drive.

You may have wanted to take a hammer to your computer at one time or another, but it may actually be a good idea if you're about to replace it with a bigger, better model.

Mark McLaughlin, Computer Forensics International says, "Your personal data is at risk when somebody resells a machine."

Just ask Todd Baitsholts. He has an old computer he wants to give to charity. First... he reformats the hard drive, then he reinstalls Windows.

"We hope to erase all the data and not have it accessible to anyone."

That should do it, right? To find out... Todd agrees to let computer expert Kevin Kranz take a look at the machine. Here's what he found, old invoices... financial data... a treasure trove for someone who might have identity theft on his mind.

"It took me about 35 to 40 minutes to get this data."

The list of recovered files takes up pages and pages.

Baitsholts: "It's surprising that they were able to get this much information off of there."

McLaughlin says, "A file is never really deleted until it's overwritten, and that's a very fundamental issue in computer forensics."

McLaughlin is sounding the alarm after he tested eight hard drives purchased at second hand shops around the country.

"We found some unbelievable things. Credit card numbers, social security numbers of celebrities, of Oscar winning actors."

Even at a graveyard for government computers... we selected three discarded hard drives at random and had them tested. Guess what.

"All this is data off of that disk."

There's un deleted data galore. So, how can you protect your data? Reformatting doesn't do it.

"It makes the file inactive. But the file contents are still there."

And while erasing data magnetically helps scramble the files... even it is not fool proof.

"What they should do first is they should wipe the drive."

You can buy software that scans the disc and bit by bit overwrites the old data, but the best method for making that data disappear, according to McLaughlin, is both free and easy.

"What I recommend is taking the drive out of the machine and taking a drill and running a drill through it several times."

Use a drill, a hammer, whatever it takes, to soften up that hard drive

   Morgan Palmer, reporting.