Restore error in NF2.6 E

I had a strange error when i tried to restore a backup of NF 2.6 E belonging to one of our clients. It read as below, “The backup has been corrupted (incorrect checksum)” Can anybody help me out with this…[^]

Hi Chander, Did you do a Database test before you made the backup? Maybe this way you would get a better response of Navision, of what the error is. /Sven

Probably You have some error in the fbk-file due to disk failure or something like that. /Lars

can any one tel me the step by step to solve the above error