There are so many reasons that will cause your Access MDB file corrupted or damaged. We classify them into two categories, i.e., hardware reasons and software reasons.
Whenever your hardware fails in storing or transferring the data of your Access databases, the databases will likely get corrupted. There are mainly three types:
- Data Storage Device Failure. For example, if your hard disk has some bad sectors and your Access MDB file is stored on these sectors. Then you may read only part of the MDB file. Or the data you read are incorrect and full of errors.
- Faulty Networking Device. For example, the Access database resides on the server, and you try to access it from a client computer, via network links. If the network interface cards, cables, routers, hubs and any other devices constituting the network links have problems, then the remote access of the MDB database may make it corrupted.
- Power Failure. If a power failure happens when you are accessing the MDB databases, that may leave your MDB files damaged.
There are many techniques to prevent or minimize the Access database corruption due to hardware problems, for example, UPS can minimize the power failure problems, and using reliable hardware devices can also reduce the chances of data corruption.
Also many Access database corruptions occur due to software related issues.
- Incorrect File System Recovery. You may find it is unbelievable that a file system recovery may cause Access database corruptions. But in fact, sometimes when your file system is broken, and you try to hire a data recovery tool or expert to recover the MDB files on it, the files recovered may be still corrupt, because:
- Due to the file system disaster, some parts of the original MDB database file are lost permanently, or overwritten by garbage data, which makes the final salvaged MDB file incomplete or contain incorrect data.
- The recovery tool or expert doesn’t have enough expertise that it/he collected some garbage data and save them as a file with .MDB extension. As these so-called .MDB files don’t contain any valid data of the Access databases, they are totally useless.
- The recovery tool or expert has collected the correct data blocks for the MDB file, but has not combined them in a correct order, which also makes the final salvaged MDB file unusable.
Therefore, when a file system disaster occurs, you should find a good data recovery tool/expert to recover your MDB database files. A bad tool/expert will make the situation worse instead of better.
- Virus or Other Malicious Software. Many viruses, such as Trojan.Win32.Cryzip.a, will infect and damage the Access MDB files or make them inaccessible. It is highly recommended to install quality anti-virus software for your database system.
- Write Operation Abort. In normal situation, you should quit Access gracefully by saving all your changes on the MDB database and then clicking “Exit” or “Close” menu item. However, if Access is shut down abnormally when you are opening and writing to the MDB database, then the Jet database engine may mark the database as suspect or corrupted. This can happen if power failure mentioned above occurs, or if you quit the Access by click “End Task” in Windows Task Manager, or if you turn off the computer without quitting Access and Windows normally.
Symptoms of Corrupt Access Databases:
For your reference, we have collected a list of errors when accessing a corrupted MDB file.