DISM is a command-line MS tool for Windows 7/8/2008/2012. DISM stands for ‘Deployment Image Servicing and Management’.
It is mostly used to reduce the size of their WinSxS folder, especially after installing SP1. There is a 32-bit and a 64-bit version of this tool.
The actual command to do this cleanup is: dism.exe /online /cleanup-image /spsuperseded
The 32-Bit version of DISM is present under c:\Windows\SysWow64 folder.
If you try to use the same on a 64-bit machine, you’ll receive below error.
Error: 11 You cannot service a running 64-bit operating system with a 32-bit version of DISM. Please use the version of DISM that corresponds to your computer’s architecture.
In order to run this properly in a 64-bit machine, you need to go directly to the native system folder to run this tool.
Open command prompt window as administrator.
Change directory by typing: cd \windows\system32
Run the command: dism.exe /online /cleanup-image /spsuperseded
Do not close the command prompt window until you get the message “The operation completed successfully”.
This utility will reduce the size of the WinSxS folder by considerable GIGs.