There are a huge number of third-party tools to allow you to securely wipe all the data on a hard disk in Windows, but did you know that Windows 7 itself contains a hidden utility for not only wiping data on drives, but also down to specific folders if you wish?
While I’ve been writing my new book, Troubleshooting Windows 7 Inside Out, I’ve had to research all sorts of stuff in Windows 7 (and I’ll be sharing more in coming weeks) and one of the little gems I found is a command line utility called Cipher.exe.
This is run from the Command Prompt (you’ll need to run it as an Administrator) and is simplicity itself to use.
The command is Simply cipher /w x:folder where you would substitute x:folder for the location you want wiped, for instance your D: drive or your C:UsersMike HalseyMusic folder.
In the help for the command it says it…
removes data from available unused disk space on the entire volume. If this option is chosen, all other options are ignored. The directory specified can be anywhere in a local volume. If it is a mount point of points to a directory in another volume, the data on that volume will be removed.
This will then write 1s, 0s and then random characters to each sector of the drive to securely wipe the data.
This is but one purpose of the cipher tool which is generally used to backup and restore encryption keys for the EFS (Encrypted File System) system that’s been around since Windows 2000. This wipe feature though is new to Windows 7.
I would always recommend you use any tool like this with extreme care, but if you are dumping a hard drive or replacing an ageing PC, this is an excellent and completely free way to wipe your data forever.
Mike, to what standard is the data overwritten? If it simply overwrites the files once then it isn’t very secure. There are many programs that can bring that data back, if that is the case.
“This will then write 1s, 0s and then random characters to each sector of the drive to securely wipe the data.”
I didn’t know that you could write anything but 1′s and 0′s to a drive. Isn’t ALL data stored as 32 or 64 bit 1′s and 0′s?
I believe the point Mike was making was that it overwrites the data with random data instead of just zeroing the drive/directory.
Additionally, I would like to point out that it is a myth that data can be recovered after being completely overwritten – it can’t. This tool encrypts the datum it writes, then overwrites that. If even a single bit of the encryption header cannot be recovered, the entire drive of data will be inaccessible. Read up on the Secure ATA command for a similar procedure that uses one-pass writing to completely and irrecoverably wipe a drive.