It's the way that Drive Wiper - and drive wipers - work. Enough files containing zeroes are allocated until the drive is full, then they are deleted. In this way Windows handles the actual overwriting, so it is safe. If you have let Drive Wiper finish then all your free space should have returned. If you have cancelled the job things might be different, let us know.
Augeas is right. If you cancelled drive wiper before complete, the files it was using to over-write free space will still be resident in your C:\ directory.
I'm just using CC Cleaner 2nd time, came across Driver Wipe option. I presumed that by choosing to Wipe Free Space Only that it means just that, like a Defragger. So I opted for it to wipe free space only. Midway I had a weird feeling that I may have interrupted it wrong. I thought it may be erasing files to wipe it clean. I got worried and pressed Cancel midway.
1st. Please can someone explain, what that feature does exactly? and how should I proceed from here? is it safe or did I just give myself problems?.
Any help would be much appreciated. Thanks and Happy Holidays to all.