What is BKF File Extension & How to Create Windows Backup with NTBackup Utility?

Technical Description of Windows BKF File Extension

Developer Microsoft
Hex Signature 54 41 50 45 00 00
Primary Association Windows XP
Location C: Documents and Settings\All Users\Application Data\Microsoft\Windows NT\NTBackup\catalogs51
MIME Type application/octet-stream
File Category Backup Files
Format Type Binary
Supporting OS Microsoft Windows Operating Systems

Full Form of BKF File Format

BKF file generally stands for Windows Backup File.

What is BKF File? - Introduction & Structure of Windows Backup File

The BKF file format is mainly used as backup file, which is mainly related to Windows Backup utility. Initially, this application was a part of MS Windows NT to Windows XP. The main motive of creating the .bkf file extension is to protect, backup data that is maintained on the local machine in the ZIP drive or Tape drive. Apart from all this, the Windows Backup file or BKF file is also known as NTBackup File.

A user can store all type of data in BKF format such as files, folders, media and data files, which are stored on Windows NT version of the systems. After that, a user can easily restore these data or files to Windows Server 2008, Windows XP, and Windows Vista systems whenever required with the help of MS Windows NTbackup.exe.

Point to Remember: MS Windows Vista, 7, 8, and 8.1 uses .vhd file format to store Windows data backup.

Structure of Microsoft Windows Backup .bkf File Format

The interesting fact about the BKF extension is that it stores all types of data as a backup in a binary form. A user is allowed to open BKF files using Hex editor that display the entire details of the backup such as:

  • Type of backup
  • Tool used to backup
  • Date & time at which backup start
  • Date & time at which backup ends

What is NTBackup Utility?

NTBackup is the inbuilt backup tool, which was introduced in Microsoft Windows NT in 1997 and become a part of all later version up to including MS Windows 2000, Windows XP and Windows Server 2003. It also uses .bkf extension in order to back up files. All these files can be backed up to the tape, ZIP drives, hard drives, and floppy disks. However, in Microsoft Windows Vista and above versions, the NTBackup was replaced by Windows Backup & Restore that uses VHD or Virtual Hard Disk file format.

Different Types of Windows Backup File (.bkf)

When a user creates a Windows BKF file with NTBackup utility it is done on the basis of a specific type of backup. However, this application offers 5 different types of backup in order to back up data differently.

  • Normal Backup: It is clear from the name that it provides normal backup of whole data stored on the system. Therefore, normal backup BKF file created through this utility will contain both the user data and the system files.
  • Incremental Backup: This type of backup will increases the content of BKF file by adding up data in the last updated backup data.
  • Copy Backup: It creates the backup file of selected data or files only. This type of BKF file format will be considered as a backup between the backups.
  • Differential Backup: It is almost similar to Incremental backup i.e. update the data created or modified since the last time any backup took place. But, dissimilar to Incremental Backup, the Differential Backup is not done to clear the archive attribute.
  • Daily Backup: It the updates files the BKF that were modified/ created on daily basis.

How to Create Windows XP Backup (BKF)?

In order to keep data safe and secure, users want to back up Windows data. Now, the question arises how to create BKF file in Windows? Thus, in the below section, a completely manual method to backup Windows files is discussed:

  1. First of all, click on the Start >> Run and enter ntbackup.exe
  2. Then, click on the Backup Wizard >> Next
  3. After that, choose Backup everything on this computer radio button and click on the Next button
  4. Now, select the location to save the backup file
  5. Give a name to your backup file that will be recognized by you easily and click on the Next button
  6. In last, click on the Finish button in order to begin the backup process
  7. When the process is completed successfully, it will generate a report of the backup
  8. After that, click on the Close button and complete the backup process

After performing all above steps, a complete backup of Windows data is created successfully in BKF file format.


Losing important data or files stored on the local machine due to any reason is really frustrating. A user may lose important data. However, a little prevention can help the user in avoiding this issue. Thus, to overcome such crisis, most of the users backup their Windows data. BKF file format is the most common format used to backup Windows files. In the above post, we have discussed all about What is BKF file extension? How to create .bkf file in Windows? All this will help users in understanding the BKF file in much better way.