As your A.mdb files exists in the same location but it is inaccessible, in this case you need to repair your access database, to repair your corrupted access data base you have to choose best Access Database Recovery
To repair your corrupted access database use Kernel Recovery for Access
I have visited many databas recovery websites and evaluated many database recovery software.
But my experience with Kernel Recovery for Access
is almost excellent.
I used this tool when my sales.mdb or sales database got corrupted and showing error message like "The Microsoft Jet Database Engine cannot open the file". This tool helped me a lot to retrieve one of my important database.
I get my database back without any problem...
The software is available for downloading its DEMO version
which allows you to preview the recoverable contents of the corrupted database.
Really a great piece of software...........