If you want to learn more about how to fix Disk Unknown Not Initialized, start by determining whether the drive is brand new or has been used before. A brand new blank disk needs to be initialized before it can be recognized by Windows. If the disk already holds some files, do not proceed to format it without trying other methods for file recovery. In case of an external drive, plug it into a different USB port and connect it firmly. You can also try restarting your PC and then checking Disk Management. Should the drive remain unrecognized, there might be problems with the partition table or some physical issues with the disk. Do not attempt any changes to the disk without recovery or professional help.