Freeing up space on Windows Server 2008 R2


Baseband Member

We are having an issue with disk space being used up on our Windows Server 2008 R2 machine (with SP 1). I've traced the bulk of the space being used to C:\System\WinSxS. My research tells me this is an a system folder that can build up over time. It builds up with every Windows Update. I'm told NOT to just delete things from this folder as it is an important system folder that affects proper Windows functionality.

However, my research also tells that I can clean SOME of the contents of this folder by running Disk Cleanup. In Disk Cleanup, I check "Windows Update Cleanup", and click OK (see attachment). However, that does nothing. WinSxS is taking up just as much space after this as before.

On the other hand, I think this problem goes deeper than just WinSxS taking up space. Every time I'm able to free up some space, it gets used up again. For example, I had a database backup that was taking up 130MB. I deleted that and then installed Desktop Experience (which I'm told is needed to get Disk Cleanup on Windows Server 2008 R2). After that, only 16MB were available on the C: drive. It's possible that Desktop Experience actually uses 114MB but that seems like a lot. Furthermore, only a few seconds after I saw the 16MB on the C: drive, I check again and say 0 bytes available.

Then I was able to get the "Windows Update Cleanup" available in Disk Cleanup which said it could free up 2.5GB. So I checked it and ran Disk Cleanup. When I checked the C: drive, it said there was only 2.3MB of space left. Then I checked again after a few seconds and 0 bytes were left.

Now whenever I run Disk Cleanup, it seems to have no effect on any folders, even with everything checked. (I'm running it from a command prompt with Administrative priveleges: cleanmgr /sageset:65535 & cleanmgr /sagerun:65535).

There seems to be something taking up free space whenever it can. I'm not sure if it's WinSxS or not.

I would very much appreciate if someone could help me troubleshoot this issue.


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    Disk Cleanup.png
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Site Team
Staff member
first question,

how big is the C drive on the machine that you are using?

you're right, do not touch files in C:\windows\winsxs yourself!

the reason for this, as I understand it is, the actual files are stored here, and what you see in (for example) c:\windows\system32 is actually just a link to one of these files, - but you don't know exactly which one...

what this means is that as the new and old file are kept, rolling back, rather than an operation involving putting on files with older versions. is simply just a case of changing a file link... (so much faster and easier)

(this is also the reason that sometimes, this folder combined with other folders can report more space used than there is disk space for! -because linked files may [some circumstances] be counted twice)

there is a command that you can run to clean up some files that have been superseded by service packs:

Dism /Online /Cleanup-Image /StartComponentCleanup

What this does is remove all the files from before a service pack, this is obviously a 1 way change, and removed your options to roll back past the service pack installation date.
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