DISM is the powerful command line utility offered by Microsoft using which we can mount, modify and service Windows operating system images. DISM can be used to work on the currently running operating system – called online Windows image. It can also be used for offline Windows images such as the install.wim file that can be found on the Windows 10/11 installation media.
Using DISM, we can do two things – manage and service the Windows images. In the management, we can query the Windows image for various editions contained inside it (such as Windows 11 Home, Windows 11 Pro etc.). We can query about the updates, drivers and extra applications contained inside the image. In the servicing, we can add or remove device drivers, modifying or customizing Windows features, adding extra programs, upgrades and more.
DISM GUI is a limited GUI frontend for DISM command line tool. It shows some basic commands which can be run only for the online Windows image. The various features including checking for the integrity of the Windows image (Checkhealth), scanning for possible errors (ScanHealth), repair components automatically (RepairHealth), analysis and cleaning of the components memory, installation of the CAB files and also repair using an offline Windows image. For the repair using the offline Windows image, you would need the installation media (such as Windows installation DVD) for the exactly the same version of Windows as you are running.
DISM GUI does not come with DISM tool itself, so you are dependent on the installed version of DISM. This puts the user under a certain limitation. This is because older version of DISM cannot be used to service the offline images of newer operating system. DISM GUI emphasizes this fact in the “Repair Offline” section as it is really designed to work with offline images anyway.
You can download DISM GUI from https://www.paehl.de/dism-gui.