Unexplained full hard drive

[Massey]

Recently I noticed that there is only 13GB left out of my 700GB hard drive. I use Windows 7. I could not think of what would take so much room. So I listed all the directories (including the hidden ones) on the root directory, got in the properties window the size they took on disk, and add it up: it all adds up only to 350GB. So where are the other 337GB?
I did run CCleaner, and the "Disk Cleanup" button on the properties window on C: (even cleaning the system files, deleting the Windows update backup: 6GB). I did run the Chkdsk.exe. And there is still these 337GB unexplained.
Please Help!

 

[digitaldoc]

Was the drive partitioned?

 

[Massey]

I was looking around for answers myself and found in another page a good program called WizTree. And running it (fast) got me the answer: the "System Volume Information" - which gives in the Windows' property info a size of ZERO, in fact has a size of 335.9GIG !!! Huge.
So this changes my question: How can I clean that? Is all that space really needed for Windows???

 

[digitaldoc]

Windows installation is a lot less than that. More like 40 GB.

 

[Massey]

Searching for "System Volume Information", I further found that there is a program vssadmin (part of Windows), that can solve the problem. see: http://www.tomshardware.com/faq/id-1891063/delete-shadow-copies-hard-disk-drive-free-space.html
To start it, one needs to use the Command Prompt in Administrator mode (right click the Command Prompt on the Accessories menu: then click the Run as Administrator).
Then at the C:\Windows\System32> prompt, simply type:
vssadmin /?
It gives the further use of that command.
You can LIST your System Shadows (by the way, VSSADMIN means: Volume System Shadows Administrator): I had 68 shadows!!! These shadows are used by restore points. They are often gigs. One of them was even 19Gig (I wonder why they are of such different sizes).
then you can delete them, either one per one with:
vssadmin delete shadows /For=C: /Oldest
or all at once with:
vssadmin delete shadows /all
Now I can breathe again! Windows had been using 350GIG in a hidden way.
Advice: do run a system restore point after (that will make ONE shadow - only).
Hope this helps other people.

 

[Solandri]

This is almost always due to system restore. Control panel -> System -> System protection. Click Configure in the dialog box. System restore is probably set to use up to 50% of the hard drive space. Lower it to a sane amount like 10%.