.BKF File is a Windows NT Backup Archive file created by Windows Backup. BKF file format is used to store the replica of files that are stored on Windows NT version of systems.
BKF File Extension is basically related to Windows Backup Utility or Microsoft Backup Utility which was a part of MS Windows NT to the version Windows XP and used to store data in ZIP drive or Tape drive.
MS Windows Vista, Window 7 & Windows 8 have the new version of Windows Backup Utility which uses Virtual Hard Disk (VHD) file format to store backup information.
Archive Files
Hexadecimal: 54 41 50 45 00 00
In actuality, there is no any default location of.BKF File. The file can be kept anywhere on the hard disk (can say Users' defined Location).