When files are deleted off computers, the file really isn't gone, it's more like, "out of sight, out of mind." But sometimes, you or your customers need more than that; you need to wipe those files off completely. In other words, these are files you'll never want to retrieve, files you want to be disintegrated.
Other times, as when you donate an old computer, you need the entire disk wiped clean. Old passwords, files and other private information still exist on the hard drive, even after the recycle bin has been dumped. When you or your customers decide it's time to donate previously used equipment, wiping the drives clean is crucial in order to prevent identity theft from end-of-life computer storage media.
A number of products offer to purge your PC in one way or another, whether that's a total dump or a file shred. The following five products should get the job done efficiently and effectively. Just be sure that -- whether it's you or your customers who'll use the product -- everyone is aware it's a one-way trip: These files will not be recoverable.