Sometimes, you need to make sure that a file you’ve deleted is really gone. I use about 7-8 different computers in a typical week, and on all of them I use utilities that do daily secure wipes of all free space.
Fortunately, there are some very good freeware apps to accomplish this.
For the most part, I use Blowfish Advanced CS, which integrates Bruce Schneier’s famous encryption algorithm (featured once on 24). Fro my experience Blowfish Advance CS has a very small footprint and is very fast.
Recently a friend pointed me to Eraser which does nothing but secure delete. I installed it and tested it out, but it seemed significantly slower than Blowfish Advance CS. On the other hand, it had two features that Blowfish Advance CS doesn’t — a) the option to create a boot disk and securely wipe a boot drive, and b) a built-in scheduler to run unattended secure wipes on a regular basis.
Maybe I’m paranoid, but I don’t want to risk someone recovering deleted data from any of the PCs I use. Neither of these programs really guarantees data cannot be recovered, but regular use certainly raises the cost of recovering any deleted data to prohibitive levels. That’s good enough for me.