Security Advice Before Selling Computer?

I found this free program:
Summit Downloads Page

*****LOW****** level formatting IS pretty effective, but generally frowned on and complicated today. High level formatting is comparatively a joke. It is effectively cleaning out a few blocks, and reseting pointers, so some old editors could be tricked to allowing people to see your data with little effort.

The next best way, over a LOW level format, IS to overwrite each file you want to delete. The key is to actually OVERWRITE. Some editors might actually create a new file, and rename it, or keep a work file or backup, and that would defeat the purpose.

That disk scrubber KimW pointed to sounds like it should be fine. And you shouldn't need the "hard scrubbing". To the best of my knowledge, you would only need that if you were afraid they had like a clean room and would read your disk on different equipment. The theory is that some residual field may be left, and they could isolate that and recover some data. Hard Drives don't allow that though.

But some software can allow preallocation of space, and if you preallocate 10GB of space, and try to edit it, you may see info from 10GB of files deleted in the normal way.

Steve

Ken,

Be smart...remove the hard drives. It's not worth the risk of trying to save a few dollars when the downside could be financial misery.

Hard drives are cheap and easy to replace. Buy some used ones if you have to, but don't hand over your hard drives to anyone else if they have ever contained sensitive information.

Your buyer could dump your old hard drive for a new one and you may never be able to trace the source if your info gets breached down the road.

KJ

I thought about suggesting taking the hard drives out, but then the value of the pc goes down. It doesn't to those that know about pcs,but to the average user it does.

Kenneth,
I'd suggest Dban free secure overwriter. It securely overwrites your hard drive to government standard making data unrecoverable in 99.9% of the time.
Darik's Boot And Nuke | Hard Drive Disk Wipe and Data Clearing

Rich