Unrecognized database format ‘mydata.accdb’.
I had to upgrade an old Windows Form application using Access database. On the row where connection was executing its Open() method I faced following error:
Unrecognized database format 'mydata.accdb'.
It turns out that it is an easy fix – just replace provider attribute’s value of the connection string like this
old value
Provider=Microsoft.Jet.OLEDB.4.0
new value
Provider=Microsoft.ACE.OLEDB.12.0
Hope to be useful.
ValueType 
thank you very much. works perfectly.
Thank you very very much… my simple beginner program now works fine….
Thank you…………….
simple and clear
i faced this error…
The ‘Microsoft.Jet.OLEDB.12.0’ provider is not registered on the local machine.
Either install MS Office or download it from here and install db engine only
Thanks….
Thanks, just what I needed!