Deployment Image Management and Service (DISM) used to update a Windows image or prepare an image. It is a command line tool. It has many uses, including its use to repair when the System File Checker scan reports errors or corrupted files.
But rarely have users reported getting the following error “Error 50 DISM does not support Windows PE service with option / online”. The DISM log file is located at x: windowsdismdism.log »when executing the DISM command. Its cause is that the windows seem to think that we are in Win PE (Pre-installation environment). This is the result of a missing registry key. Follow our guide to fix it quickly.
Registry key deletion
Hold down the Windows key and press R. Type regedit and hit Enter. Press Yes if a UAC warning appears.
In the registry editor windows, click HKEY_LOCAL_MACHINE in the left pane to expand it.
En HKEY_LOCAL_MACHINE, click SYSTEM to expand. Similarly, navigate to HKEY_LOCAL_MACHINENSYSTEMNCurrentControlSetNcontrol.
Under control, there will be a folder called MiniNT. Click on it and click Permissions.
Select your username in the group or username list and make sure the box is checked. Then click OK.
Right click on the same MiniNT key and click Remove. Confirm the messages for deletion. Reboot the system and run the command again. Your problem should go away.
Update BIOS
If the above answer doesn't work, make sure to restore the BIOS to its default settings. You can do this by booting into the BIOS. Since all models are different, it is better to refer to the manual to see how to restore BIOS to default values.
