This message means that your computer couldn’t find a healthy boot device.

What does 'No Bootable Device Found on Windows 10' mean? How to fix “No Boot device found” on Windows 10.What causes the 'No bootable devices found' error on Windows 10?.What does 'No Bootable Device Found on Windows 10' mean?.In this article, we'll discuss the most common causes of the 'No boot device found' error and how to troubleshoot it. There are a number of potential causes for this error, but fortunately, it's usually fairly easy to fix. All you need to do is use the Choose Floppy Image command from the Virtual Machine > Floppy menu or the Floppy device button on the Status Bar to select the next disk in the set and then press Enter to continue once you set focus back into the Virtual Machine's display.' No boot device found ' or ' No bootable device ' is a common error that can occur when trying to start your Windows 10 computer. This is DOS not *nix so your not mounting/unmounting as in using the mount and or umount commands so when you are saying 'I can mount' and 'I go to unmount' if you're referring to selecting the Disconnect Floppy/Connect Floppy command from the Virtual Machine > Floppy menu or the Floppy device button on the Status Bar then don't do that because DOS can't recognize that and it is as if you physically disconnected the Floppy out of a running physical machine and tried to plug it back in and at that level the BIOS and DOS do not dynamically update the information as if in Windows and connecting/disconnecting a USB device will. I go to unmount Disk #1 and mount Disk #2 and all is fine, I go back to the installer but it just does not recognize Disk #2 and never will. I can mount Disk 1 of these discs and attempt to install, installer starts and all will work until it needs Disk #2.

Floppy disk format for windows 10