Accidental and Intentional File Deletions.
Partition Deletions.
RAID Hard Drive Failures.
Reformatted Hard Drives.
Virus Attacks.
Fire, Flood or Earthquake Disasters.
Your data can be corrupted if you have a logical hard drive failure or if a virus has attacked your files. This is because the header information or the crc (cyclic redundancy check) is corrupted.
There are a host of other reasons why corrupt files or corrupted databases can´t open. Most likely the media is damaged, or an electrical anomaly has occurred.
Our best advice...save your corrupted file somewhere safe (external storage media) and see if you can open the damaged file using another computer.