>Hello,
>
>I have a friend who is selling their small restaurant which has a very old POS system in it. It's running on DOS 6.2 and a pier to pier called Desk to Desk. We would like to remove all of the deleted files on these computers. I'm having no luck finding anything. Any suggestions would be appreciated.

Assuming you want to completely wipe the drives on the computers (being so old they're useless for anything else) you can use http://download.cnet.com/Active-Kill-Disk-Hard-Drive-Eraser/3000-2092_4-10073508.html

I believe it gives you the option to create either a boot floppy or bootable CD, whichever works best for those computers.

Another sometimes-overlooked option is to disassemble the drives (you typically need a small Torx screwdriver to do that), and then bash the platters with a hammer of your choice. For some reason, a lot of computer people find doing that strangely satisfying :)