Disappearing HD Space.

[Rerednaw]

So I haven't installed anything (in fact I removed about 200 GB of programs-mainly from the Batman Arkham series.)

Anyway I've noticed that each day my 2 TB drive loses about 100 GB of space. What's the best way to figure out what is happening?

Virus scanners have not found anything. I defrag the drive continuously.

Windows 8.1 64-bit. Is Microsoft sneaking in an Win 10 install or something?

Any help appreciated.

Thanks.

I just did a full shutdown and restart and just lost another 10 GB of space.
I've cleared my Chrome cache, windows cache, reset file history, used disk cleanup.

 

[Fardringle]

Check the storage limits in the System Restore program. You might be seeing the effects of the system adding more restore points as you make changes on the computer.

 

[lakedude]

http://sourceforge.net/projects/windirstat/

 

[TheELF]

Run spacesniffer on the drive, it's free and it will update in real time so keep watching and you will see what files are being updated/written.