| .mai |
Microsoft Mail File |
| .mhtml |
MIME HTML File |
| .mui |
Myriad User Instrument File |
| .mailhost |
MSN Mailhost Settings File |
| .mco |
Live Messenger Winks File |
| .mmc |
Microsoft Media Catalog |
| .mspx |
Microsoft ASP.NET Web Page |
| .msdvd |
Windows DVD Maker Project File |
| .mgx |
Rise of Nations Saved Game |
| .mgl |
Age of Empires 2 Replay File |
| .msu |
Windows Vista Update Package |
| .mpt |
Microsoft Project Template |
| .msn |
Host Blocking File |
| .myapp |
Visual Studio Application XML File |
| .mum |
Windows Vista Update Package |
| .mpf |
Microsoft Media Package FIle |
| .mbf |
Microsoft Money Backup File |
| .mml |
FrameMaker Maker Markup Language File |
| .mcl |
Windows Media Center Link File |
| .mpd |
Microsoft Project Database |
| .mlc |
Microsoft Language Interface Pack |
| .msrcincident |
Windows Remote Assistance Invitation File |
| .maf |
Mutation Annotation Format File |
| .minesweepersave-ms |
Minesweeper Saved Game |