Question about disk defrag and unused space


New Member
I ran a defrag before using the eraser program to overwrite unused free space (wish I read the FAQ page first).

Does this mean that the erase was not as secure and some files may not have been overwritten completly? The FAQ says some traces may still remain if drive is defragmented first.

Thanks again
Don’t worry about this unduly.

The idea about not defragmenting before a free space wipe is that data you wish to destroy may be overwritten with an active file during the defragmenting process. This would mean that the sensitive (previously deleted) file will have only been overwritten once.

As far as I know no one has ever been able to write a software recovery tool to recover any data that has been over written once. There is a theoretical chance that an adversary may be able to recover some remnants of data using an electron microscope in a forensic lab.

If you fear a three letter agency getting hold of your deleted data and them taking the time and spending a considerable amount of money to recover this data then I suggest you completely DBAN your drive then physically destroy it.

Otherwise don’t worry about it, just use Ccleaner and then perform a single pseudo random pass over the free space and cluster tips every now and then.

If you are really worried you could completely encrypt your hard drive with a free utility called Truecrypt.

Thank you for the quick reply.

I'm getting rid of my old computer this week and giving it to a friend in need.

I'm not too worried, as I completly trust my friend, and I'm sure that the program was more than effective. Just didn't want to risk any of my personal information, work reltated files, emails, and so on to get into the wrong hands should the computer find another owner down the road.

PaulaM74 said:
I'm getting rid of my old computer this week and giving it to a friend in need.

In this situation I always recommend backing up any data you wish to keep and then DBAN’ing the entire drive.

Be aware though that this will mean you have to re-install the OS, but I believe it to be the best and safest way to pass on a second-hand computer.

If you want to play really safe then you should give them the computer but insist they buy a new hard drive for themselves. They are so cheap nowadays it isn’t worth the security risk.