In tip 2316, we discussed Windows 2000 CD Autorun.

When you change the media in a CD-ROM drive, a MCN message is sent to trigger media features, such as Autoplay.

You can suppress the MCN message for specific vendor / products by configuring the AutoRunAlwaysDisable value name, a REG_MULTI_SZ data type, at HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Cdrom.

Typically, AutoRunAlwaysDisable contains a list of of devices that do NOT support Autoplay, because they must load the media to verify that the device is a CD-ROM, such as a changer.

The entries in AutoRunAlwaysDisable suppress the MCN message for all devices that match the character string you enter, starting at the beginning. You could disable all CD-ROMS manufactured by ABC Company, by setting one line to ABC.

If a device is identified in AutoRunAlwaysDisable, Autoplay does NOT operate on the device, regardless of the value of Autorun, NoDriveAutoRun, or NoDriveTypeAutoRun.

Use AutoRunAlwaysDisable as a last resort for disabling Autoplay.