On some early installations of SBS 2011 OEMs weren’t always very generous with the hard disk partition size for C:, and administrators quickly found themsleves juggling for diskpace. Luckily there are wizards to move various componets of SBS (Exchange, WSUS, Sharepoint and Home Folders) to different locations, namely a different partion or data drive, but even by doing that an installation that has now been running for several years may find diskspace running out.
Last month Microsoft released an optional update for Windows 2008 R2 which added the ability to cleanup the WinSxS folder by using the Disk Cleanup Wizard. The WinSxS folder can often be numerous Gigabytes in size because it contains a copy of all the Windows Updates applied to the computer, effectively a complete copy if Windows so that you are able to roll back an update if you need to.
The only caveat to this process is that on the Windows 2008 R2 server you need to install the Desktop Experience Feature to be able to run the Disk Cleanup Wizard.