i recently defraged c drive with deffragler.....before starting halve of c drive was empty,,now it is nearly full.....A 245G DISK.....a loss of roughly 100g i wont be using it again ,,,I am really fraged off////i started the proccess with disk half full then went on to something elese ,,i came back to it an hour latter the deffrager was still running with almost all the disk full with all the restore points gone.
any chance you were doing a 'wipe free space' process and DF didn't finish for whatever reason, and now in your root directory there is a very large, randomly called file.
if so, delete that file and your space will come back.