Applies To: Windows 8, Windows 8.1, Windows Server 2012, Windows Server 2012 R2 If a Windows image becomes unserviceable, you can use the Deployment Imaging and Servicing Management (DISM) tool to update the files and correct the problem. You can use DISM to repair an offline Windows image in a WIM or VHD file, or an online Windows image. An online Windows image will also attempt to repair itself