Just in case someone should stumble upon the same behavior as i did.
An update for Windows 8 released this month (KB2821895) could potentially hold up you computer for a few hours.
If you install this update and run the disk cleanup or sfc tools, the process can take a few hours instead of a few minutes as well as eat up your CPU. This is supposed to happen because Windows is switching compression algorithm on the winsxs files in preparation for Windows 8.1 and running a system check apparently accelerates that process. It will take some time but you should see more free space afterwards
One side effect of this is that sfc /scannow will report every file on your system as corrupt although nothing is wrong. This is a bug and will surely be fixed at some point.
The process will also place a 3GB file called Reserve.tmp in the WinSxS folder. Do not delete that. Windows needs it and will remove it after a few days.
So in case you notice some strange behavior from Disk Cleanup or SFC, be not afraid
An update for Windows 8 released this month (KB2821895) could potentially hold up you computer for a few hours.
If you install this update and run the disk cleanup or sfc tools, the process can take a few hours instead of a few minutes as well as eat up your CPU. This is supposed to happen because Windows is switching compression algorithm on the winsxs files in preparation for Windows 8.1 and running a system check apparently accelerates that process. It will take some time but you should see more free space afterwards
One side effect of this is that sfc /scannow will report every file on your system as corrupt although nothing is wrong. This is a bug and will surely be fixed at some point.
The process will also place a 3GB file called Reserve.tmp in the WinSxS folder. Do not delete that. Windows needs it and will remove it after a few days.
So in case you notice some strange behavior from Disk Cleanup or SFC, be not afraid
