Notes about the DM_4 file extension:
Incorrect file associations could be the result of underlying issues within your PC system. As such it is highly recommended to scan your PC for invalid registry entries
, unused processes and other unfavourable system settings to identify slowdown issues.
The DM_4 file type is primarily associated with 'Call of Duty' by Activision, Inc.. If you have trouble running the demo try the Seismovision demo player.