diskmgmt.msc

Saved management console Reference

An .msc file is a saved console for the Microsoft Management Console. The XML document lists the snap-ins and the layout of one management tool. The console program, mmc.exe, reads the file and builds the tool window. Windows administration tools such as Device Manager and Event Viewer ship as .msc files. A double-click opens the console.

A file extension is only a part of the file name. It does not give a guarantee about the format or the content of a file. But on Windows, the extension selects the program that opens the file.