Adjective
unbootable (not comparable)
(computing) Not bootable.
It can also repopulate and repair all the files in the Dllcache folder. citation Recovery Console The Recovery Console is usually used to recover unbootable systems. Source: Internet
If the sector cannot be read (due to a missing or unformatted disk, or due to a hardware failure), the BIOS considers the device unbootable and proceeds to check the next device. Source: Internet