If the data on the disk is important to you then I recommend this step to preserve the information from further degradation as the floppy disk ages. If that doesn’t work, you can use the “dd” command to make an image of the contents of the disk regardless of filesystem corruption or other concerns. If Ubuntu does not recognize the disk, you can try using the Disk Utility (it’s in the menus under System->Administration->Disk Utility) which might see the disk even if it doesn’t auto-mount. If Ubuntu is able to recognize the disk, then you can open it and save the data you want to a hard disk or CD or whatever. IIRC Ubuntu supports all MS-DOS and Windows file formats “out of the box”. Put the disk in the drive and see if Ubuntu recognizes it. If you want to try to save it yourself, I recommend getting an Ubuntu live cd and booting your computer from that. Floppy disks are not a good long-term storage medium. The floppy is not actually unformatted, but either the format is one that your PC does not support or the filesystem is corrupt.

Floppy disk is not formatted