There is only one file type that uses the .VXD extension:
Virtual Device Driver
Helper file for a specific program; adds additional capabilities and support for the program; typically installed with the Windows operating system and with other software programs.
The Vmm32.vxd file contains several drivers required by Windows 98 and Windows ME. If the Vmm32.vxd file is deleted, moved, or corrupted, certain programs may not open and the computer may not even start up. A backup of this file can usually be retrieved from the Windows installation disc.
Updated: October 19, 2006