Hidden Windows Feature: Wipe free disk space with a simple command
This tip applies to Windows XP, Windows Vista, Windows 7, and Windows 8x
By now you know (or you should know) that when you delete files or folders in Windows, they’re not really deleted. Not even close. Deleting a file or folder merely tells Windows that the space occupied by the file or folder that you deleted is now available for use, and Windows considers it free space, space it can use. So everything you delete is still on your computer, but the hard drive space it used shows as free space. Of course this means any of those files are very recoverable at least for a while. In fact, with the right software, everything you’ve ever had on your computer, every word you’ve typed, every picture you’ve saved and deleted, everything is recoverable.
Did you know there’s a hidden utility in Windows that will overwrite all the free space, thus making the files you’ve deleted virtually unrecoverable – or at least very much more difficult to recover? There is and all it takes is a simple command to run it.
Press the Windows Key plus the “R” key and type:
cipher /w:C (where C is the letter of the drive you want to wipe). So if you want to wipe drive C, type: cipher /w:C . If you want to wipe drive D, type cipher /w:D . Please note the space between cipher and the forward slash.
Also, it’s important to note that wiping the free space on your drives does not affect any of your data or programs. It merely wipes the space Windows shows as free to use. So you aren’t going to lose any data by doing this.
One more thing: If you have a very large hard drive with a lot of free space, this process is going to take a long time, so be prepared. Also, closing all open applications while the free space is being wiped, helps speed up the process. So it’s best to do this when you’re not actively using your computer.