Convert mgr to dds Online: mgr2dds

You can use Tom's Editor to easily convert images from
MGR Window Manager bitmap .MGR to Direct Show Surface .DDS.
Tom's Editor is a free, online image manipulation and converter program.

Go to Tom's Editor

MGR

MGR Window Manager bitmap is an image format with extension MGR.

DDS

DDS are files invented by Microsoft to be used in games, mostly as textures. Images can be compressed to save space but the compression methods defined by DDS are all very fast in terms of coding and decoding.