Accidental format or deletion. Cases like this are usually recoverable depending on what type of format was done or if the sectors have been overwritten after the deletion or format.
A virus infected PC can cause the system to no longer boot and crash or lock up the system. Ransomware is another issue that can encrypt the data requesting payment for the decryption key.
Operating system corruption can be caused from buggy software installations or even failed windows updates.
LEVEL 1 DATA RECOVERYMr.Anderson2019-09-01T19:32:59-04:00