Obtaining MCI System Information

[The feature associated with this page, MCI, is a legacy feature. It has been superseded by MediaPlayer. MediaPlayer has been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use MediaPlayer instead of MCI, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]

The sysinfo (MCI_SYSINFO) command obtains system information about MCI devices. MCI handles this command without relaying it to any MCI device. For the command-message interface, MCI returns the system information in the MCI_SYSINFO_PARMS structure.

You can use the sysinfo (MCI_SYSINFO) command to retrieve information such as the number of MCI devices on a system, the number of MCI devices of a particular type, the number of open MCI devices, and the names of the devices. This command is often called more than once to retrieve a particular piece of information. For example, you might retrieve the number of devices of a particular type in the first call and then enumerate the names of the devices in the next.