Q: How can I permanently delete a file from my Windows system? When I use the Shift+Delete keyboard combination or empty the Windows Recycle Bin, the files don't get actually deleted. Windows only removes the index for that file in the file system.

A: To permanently delete a file in Windows, you can use the command-line utility named SDelete, which is one of the Sysinternals tools provided by Microsoft. SDelete can overwrite the contents of free space on a disk so that no one can recover the deleted data that the disk contains. Under the hood, SDelete relies on the Windows defragmentation API to determine which disk clusters hold deleted data.

You can download SDelete from the Windows Sysinternals website. The tool is very simple to use. For example, to overwrite the deleted files on your system's C drive, you'd run the command:

sdelete -z C: