Free Space Drive Wipe Wrecks Entire Drive if Cancelled

If you are wiping the free space on a drive (in this case, a spare platter drive for large data amounts), but then cancel it before it completes, the entire drive becomes unreadable by Win7 and asks for a format. Under Disk Management, the file system type of the drive is reported as "RAW". Other software can be used to recover the contents of the disk (the non-free space data, the data which you wanted to keep), but obviously CCleaner shouldn't have created this situation in the first place.

Again, the problem seems to arise when cancelling a "Wipe Free Space" (1 pass) procedure. It was about 90% finished.

Excessive writes to a already well worn drive will do this. Wipe free space fills the entire free space of a drive with data.. sadly it's likely that this was going to occur on your drive soon anyway, though it was as you've stated brought upon quicker by WFS.

Actually it is a brand new drive...6 months old anyway. And this isn't the first drive it has done this to. So it actually seems to be a feature of CCleaner Free Space Wipe, not an accident of an old drive. It should not be corrupting the entire drive and the existing data on the drive - only the free space should be written over.

I've had that issue before using a different tool many years ago before CCleaner had the ability.

In my case being on XP I had the recovery console where I could repair (if I'm remembering correctly) either the MFT or Bootsector to change the drive format from RAW back into what it was supposed to be. It seems in some instances when cancelling/interrupting wipe free space tools the end result can be a hard disk being deemed RAW by Windows.

James Litten has a page here with some deep reading on how to repair it:

http://html5.litten.com/updated-how-to-fix-external-disk-drive-suddenly-became-raw/