Notes about the DPM 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 DPM file type is primarily associated with 'Darkplaces Engine' by LordHavoc. DarkPlaces engine was started soon after the Quake source release to add modding features for my DarkPlaces mod, and some enhancements to the on-line gaming experience. DarkPlaces engine is the result