I just copy paste the article because this article are helping me a lot, when I want to clean up the disk on server without reboot the server.
Disk clean up can be a very useful tool especially in Servers when Disk space is fully utilized. But what do you do when you are working in a production environment and you can’t reboot the server. In a pinch, I found the following process to cleanup a congested System Partition.
Copy cleanmgr.exe to System32 folder
A favorable alternative to adding the Desktop Experience feature to your production server, while requiring no system reboot or maintenance window, is simply copying thecleanmgr application files to their appropriate location.
There are two files that need to be copied to the Windows System32 folder. The only downside to this process is that the disk cleanup utility will not appear in the normal disk drive properties. However, as these files will be copied to the System32 folder location, the utility can be easily launched from the integrated server search bar.
The two files you are looking for are the cleanmgr.exe.mui and cleanmgr.exe. Below is listing of folder locations that these two files will be located for the most popular version of Server 2008.
After you have found these files, simply copy then to their designated locations as described below.
Copy cleanmgr.exe to the System32 folder
Copy cleanmgr.exe.mui file to System32\en-us\
Windows Server 2008 64-bit:
Windows Server 2008 R2:
To run the disk cleanup utility, simply navigate to a command prompt or Run and type cleanmgr.exe
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