Backup file created by O&O DiskImage, a file backup and Disk image creation application; contains a compressed, exact duplicate of the original file data; does not contain any drive information like the disk image file extension, .OMG.

To create the OBK file: Select the "Start file backup" option on the main Start page or select Start → File backup from the menu. Select the drive and check the box next to the source file(s) you'd like to create a backup for, and click Start file backup. A "File backup" window will open with the "Target" directory highlighted and other backup options. Once you tailor the options to your liking, click Start. When the process is completed, click Close. To restore an file using the OBK file: Select Start → File restoration from the menu. Navigate to the OBK file you'd like to restore and click Open. Select the file(s) you'd like to restore the drive from and click Start file restoration. A "File restoration" window will open, click Start. When the process is completed, click Close. NOTE: You can extract OBK files with applications like Win-Zip, except for encrypted files, which can only be accessed with O&O DiskImage.