I have tried many programs, from Norton onwards (Eraser, Secure Clean, R-WipeClean, CyberScrub, BestCrypt, to name most). All claim to do this. However, when I then re-run Recover My Files, lo and behold, there are all my old erased files available.
I'm told that only a low-level format of my hdd will do this - something I'm reluctant to do 'cos (a) it's a lot of work re-installing everything; (b) it may not work! Having been given lots of assurances by several companies that thair product will do exactly what I require and then finding that this is not so, I am beginning to suspect that there isn't anyway of doing what so many claim to do. These programs presumably do an equivalent to a low-level format in some areas (like the free space), but I'm finding that files are still recoverable there too.
The worrying thing is that all of these programs are supposedly authorised by various authorities as meeting data protection regs - and they don't. This despite they saying that each of their program work OK under WXP (some with the proviso that all other programs are switched off).