Floppy disk image formats supported by Virtual PC and Virtual Server

Virtual PC and Virtual Server allow you to create and use 1.44MB (high density 3.5" media) and 720KB (double density 3.5" media) floppy disk images.  However they also support a number of other formats.  The supported formats are as follows:

Size: 360KB
Format: Single-density
Media type: 3.5"
Information: You probably are unfamiliar with this format.  The only place that I've ever seen this used is on the old Apple Macintosh installation media.

Size: 720KB
Format: Double-density
Media type: 3.5"
Information: This is the standard "old" 3.5" floppy disk format.

Size: 1.2MB
Format: High-density
Media type: 5.25"
Information: This is the largest standard format that was supported on the old, flexible, 5.25" floppy disks.

Size: 1.44MB
Format: High-density
Media type: 3.5"
Information: For people who are still using floppy disks, this is probably what they're using.

Size: 1.68MB
Format: High-density - DMF
Media type: 3.5"
Information: DMF, or Distribution Media Format, was a format used by Microsoft to allow them to cram more data on to a standard floppy disk.  It was used for the installation media for things like DOS, Windows 3.11 and Office 4.2.

Size: 1.72MB
Format: High-density - XDF
Media type: 3.5"
Information: XDF, or eXtended Density Format, was IBM's equivalent to DMF.  It was used for OS/2 and PC-DOS.  Interestingly enough it is not physically possible to read a XDF formatted floppy under Windows at all, so we only support the use of XDF floppy disk images (not physical disks).

You may come across floppy disk images that are already in these formats, in which case they will just work.  Or you can make your own floppy disk images in these formats by using tools like WinImage (https://www.winimage.com).

Cheers,
Ben