The "Virtual Drives Manager" is the freeware tool which lets you to define, redefine and delete the virtual drives in your file system.
The Virtual Drives (also known as MS-DOS device names) is the symbolic links, in the object name space in 32-bit versions of Windows, which points to the directories of your existing drives (hard, floppy, CD and so on).
The code that converts an MS-DOS Path into a corresponding path in 32-bit versions of Windows uses these symbolic links to map the virtual devices and drive letters.