How Microsoft Windows Uses an MS-DOS Mouse Driver

• Microsoft Windows Device Driver Kit (DDK) for Windows versions 3.0 and 3.1

For performance reasons, the Microsoft Windows graphical environment does not use the MS-DOS mouse driver even if one is installed. Windows has its own mouse driver (usually a file named MOUSE.DRV) that handles mouse input. Therefore, Windows applications can use the mouse as long as the appropriate Windows mouse driver is installed, regardless of whether an MS-DOS mouse driver is present.

The Windows mouse driver does not provide any mouse support for MS-DOS (non-Windows) applications. You must load the MS-DOS mouse driver to use the mouse with an MS-DOS application running under Windows. You can load the MS-DOS mouse driver either before running Windows or in an MS-DOS session under Windows. However, we recommend that you load the mouse driver before starting Windows because hardware conflicts may occur if a mouse driver attempts to initialize the hardware after Windows has started.

The virtual device driver named VMD manages ownership of the mouse hardware between the Windows mouse driver and the MS-DOS mouse driver. VMD is not a mouse driver; it simply switches hardware ownership between the MS-DOS and Windows drivers.