I need to free some enough space on system disk. I checked by native windows defragmentator and it says that it needed to be defragmented. The Defragler utility shows 57% files fragmentation on disk C: (and about 40% on two other partitions) but it has no indication how much space could be freed. If there is about 200 mb on 10 gb system partition how much can I count on in case of such defragmentation? What is more effective - windows or defragler defragmentation? I should also not there is some 0.5 gb of failed VStudio re- installation files that I could not find and delete if it is possible in the whole. I should also note that disk C: has some 8 kb bad sectors that was repaired by hd regenerator but probably they are replaced by other spared sectors so I am not aware how such changed references could be impacted by defragmentation? Here I should note that I entered deficient LBA in WinHex-Go Sector and eventually got some item (file alike item) with name bad_sector with 8 kb label, but to view (right click) it needs superior license, to view in notepad -- it shows wild unreadable charactersd, and if open -- there are 2 columns -- hex and ascii values (with some reference to registry in last case).