Something's eating up my hard drive space

[Synastral]

So i'm not really sure what's been going on, as i've never experienced this before.. I have A Western Digital Blue 1 TB hard drive, and for some reason it says I have only 515 gigabytes left of storage, but if I go in and select all of the folders in the drive, it says i'm only using 156 gigabytes. Is there some sort of display error or whats going on?

 

[USAFRet]

Hidden files
hibernation
pagefile
Restore Points

Start with WinDirStat, and see where your space is going. This misses a lot of things, but is a good place to start.

 

[Synastral]

I have hidden folders shown, that would show the hidden files, right?

 

[USAFRet]

I have hidden folders shown, that would show the hidden files, right?

Not necessarily. See the above linked application to start with.

 

[Synastral]

The thing on the right is my main hard drive. It's only happening to that one.

Big gray block is world of warcraft. The block right next to it is the witcher 2. purple blocks at the bottom are pagefile.sys and hiberfil.sys

 

[Synastral]

I figured it out. Turned out my system restores were taking up 218 gigs. I set the allocated space for system restore points to 1%, but is that enough? What % of my hard drive should i use for restore points?

 

[i7Baby]

About 10% - which will hold 2 or 3 restore points.