hard drive problem

[sky2200]

Good day masters!
I just wanna ask a question about what happened to my hard drive.
Before i optimize/defragment my hard drive, it has 69.1 gb available memory,
but after i optimized/defragmented it, it became 34 gb.
As far as i know, disk optimization is a way to maximize your pc speed, but I don't know if it uses some of your memory to enable the process.
Does it? Thank you very much!

my laptop specs: windows 8.1 64x, intel celeron 1005m 1.90 ghz. dual core
4gb ddr3, 500gb hdd 34 gb available.

 

[Agera One]

Do a disk clean-up and see the free space available.

 

[sky2200]

Do a disk clean-up and see the free space available.

I just finished doing what you suggested sir, but I just saved 82 mb of memory, is it possible that disk defragmentation/optimization uses some of your memory? coz' I think that's what happened, thank you sir.

 

[Agera One]

No, It'll not use anything like that. Is it the OS partition or another?