Reduce size of a Windows 10 installation with Compact OS

Compact OS is a Windows 10 system mechanism that allows an administrator to compress the installation files of Windows, reducing the storage utilized by the OS.

Short Tutorial

Follow this steps to compress your system installation files:

  1. Search for Command Prompt, right-click the Command Prompt app and select “ Run as administrator”. When prompted, select yes for administrator rights.
  2. Enter the following command to find out if your system is already compressed:
    Compact.exe /CompactOS:query
    If you see the message "The system is in Compact state", Windows is already compressed. If not, got to step 4 to compress your system.
  3. Now, use this command to compress your system, this process could take up to 20 minutes depending on your device:
    Compact.exe /CompactOS:always