When we talk about backup, we take it as a procedure or process for making copies of data and files. The only objective of data backup is to provide a source from where users can restore their data and files at the time of data loss event due to any reason, be it accidental deletion or corruption. Windows backup utility, known as NT-Backup tool, is quite popular among Windows users. Backup job can also be done by using other commercial-ware utility like Backup Exec provided by Symantec (formerly known as VERITAS). NT-Backup utility is available only for Windows platforms, while Backup Exec is available for Windows, Mac, Linux and many others. By using any of these backup utilities, you can back up almost each and everything saved on your computer, which includes: Office documents, database files, email flies, PDF files, image files of all popular formats, audio files, video files, software executable files, archive files and many more. All your data and files are stored in a file, called BKF or backup file. A backup file plays a very crucial role in our day-to-day life. As we know that data corruption is an inevitable occurrence, i.e. it can be occurred at any time without any prior notice or warning. Also, accidental deletion can cause data loss for ever. Whatever the reason is, BKF file becomes a life-saver for us if any such data loss event takes place. Like other computer files, a BKF file is also prone to corruption. There are many reasons which may cause corruption in your BKF files and make them inaccessible. At the time of corruption, the BKF files become unable to be restored. Think you have recently deleted few of your very important files, may be accidentally or intentionally. Luckily you have a BKF file containing the backup copies of those files. You try to open the file, but you fail. At the same time, an error message is encountered something like this: “The backup file contains unrecognized data and cannot be used.” Or, “The backup file is unusable. You must erase it, or choose another file.” Receiving such error messages means the BKF file from which you are trying to restore data, is corrupt. If you have ever faced corruption in BKF files, have you ever tried to find out the reasons which cause corruption? No, may be you have not because the reasons of a problem are never important than its solution. But this is a stupid idea to go directly for the solution without knowing the causes of your problem. Before you can go anything for fixing corrupt BKF files, you must know the corruption reasons. Here I am discussing few common reasons which may cause corruption in your BKF files: Interrupted Backup Job: The most common reason of corruption is considered the interruption caused during the backup job, i.e. either creating backup or restoring data from it. Interruption mainly occurs due to sudden power failure, collision of software programs, abruptly or forcefully cancellation of backup utility, etc. Virus or Bugs Infection: No computer file is immune to virus or bugs infection. Backup files are also at high risk due to virus attacks. Virus can infect the BKF files by overwriting them or deleting some part of the files. Such changes caused by virus attack can only be seen using hex editor. Sudden Power Outage: Whenever your system gets turned off due to sudden power outage or failure, it puts all your data and files at high risk. Next time you turn on your computer, may be your data and files would be lost. This act mainly affects the system hard disk because hard disk needs proper time to be stopped functioning. Storage Device Failure: Storage device could be anything, like your system hard disk or any other external storage media. Various reasons for responsible for storage device failure, such as: sudden system shut down, software malfunction, physical damage, etc. The failure or malfunction of storage device failure can cause inaccessibility of data, or sometimes corruption as well. Missing Catalog Files: Catalog files play an important role in BKF files. They are created during the backup job, and stored in catalog folder. The stamp attribute of backing up and restoring jobs should be matched; otherwise corruption may occur in your BKF files. Other Reasons: Other reasons include human error, software malfunction, software collisions, etc. Whatever the reason is for corruption, all you can do here is just repair BKF file. As there is no manual approach or trick to repair BKF file, users are left with only one solution: professional BKF recovery software. There are many software companies in the market which provide recovery software for corrupt BKF files. Such software are programmed for scanning corrupt BKF files, and repair them in possible. After that, they restore the data maximum possible data in their original form at user-defined location. BKF File RepairHow to Repair Corrupt BKF File Backup Exec BKF Repair Pro tool provided by SysInfoTools Software, is one the finest and effective solutions available in the market for BKF repair and recovery. It supports BKF files created by both NT-Backup as well as Symantec Backup Exec (VERITAS). The best part of this tool is that it supports both split as well as compressed BKF files. This means if your files are in compressed form as well as split into multiple parts, you can use this tool to successfully restore your maximum possible data. Also, users can restore their SQL databases from corrupt BKF files.