[expatpat]

To really get rid of data on a hard drive, you have to destroy the hard drive's storage disk.Nah, you just have to write over the area that was used. Copy all your biggest files and save with new names. Then defrag, and the odds are you have overwritten the area, tho' not guaranteed.

[ImphClinton]

Software will write 0's to the entire hard drive that is not used.

But it might be better to do as you suggest. Completely fill the Hard Drive (easily done with video). This will erase any traces of old documents. It has the added bennefit of not leaving evidence of what occurred. Delete the extra files then defrag the drive.