|"but in defrag it says Capacity is 112 gb and 105 free space (93% free)"|
That refers to your hard drive.
The "physical memory" statistics refer to the installed RAM modules, not the hard drive.
The "virtual memory" or "page file" refers to how much of the hard drive is allocated to be used for swapping data from RAM to hard drive when required.
Do not get confused by the word "physical memory". It has nothing to do with the hard drive space.