Unused space showing as used after Wiping Free Space

This person below i found had unanswered question, well i have my question pretty much the same.

After i use ccleaner to wipe free space my dfragler will show significant amount of what it was free space as being used by a file in c:\system volume information folder.

I am talking about like 50GB of space that i am missing now because of the wipe feature of the ccleaner.

no matter how many times i have done MS degragmentation, defragler, cclean checkdisk, the space is still occupied by this "free space overwrite bits" so my question is, how do i get my 50GB back?

i will not do a MS windows restore, so that's not even a question.

Thank You hazelnut for your respond ...

but when i do wipe free space .... always i found an extra 1 or 2 MB on my C ...

is this normal?? .... or there is a problem??

*Excuse me for asking many qustion :P ..