Switch Windows Server 2012 between core and GUI

1. Mount the Windows Server 2012 ISO to the host.
2. open an administrative command prompt
3. mkdir c:\mount
4. check your wimfile to determine the correct index for the OS (mine was 4) -the command is dism /get-imageinfo /ImageFile:d:\sources\install.wim
5. dism /mount-wim /wimfile:d:\sources\install.wim /index:4 /mountdir:c:\mount /readonly
6. powershell (enter PowerShell prompt)
7. install-windowsfeature server-gui-mgmt-infra,server-gui-shell –restart –source c:\mount\windows\winsxs
8. Unmount Wim (dism /unmount-wim /mountdir:c:\mount)
9. Remove Mount Directory (rmdir c:\mount)

Alternative is to install directly from WIM

1. Install-WindowsFeature server-gui-mgmt-infra,server-gui-shell -restart -Source wim:d:\sources\install.wim:4

This will not remove the install files, so you can later use the single line add-windowsfeature commend (without all the steps above). To completely remove the binary files, add –Remove at the end

1. Uninstall-WindowsFeature Server-Gui-Shell, Server-Gui-Mgmt-Infra
2. Shutdown –r -t 0 (Reboot)

You can do this if you allready have GUI feature files on your system

1. Install-WindowsFeature Server-Gui-Shell, Server-Gui-Mgmt-Infra -restart
2. Shutdown –r -t 0 (Reboot)