In my case I downloaded a Microsoft Access File with extension of .accdb but when I open it using Access 2007 I received and error saying “Unrecognized database format “C:\Users\howtoquick\desktop\file.accdb”. I confidently sure that the database file I downloaded is not corrupted so no need for me to repair. After checking with installed application on my Windows 10 computer it works, I recalled that I installed the service for MS Office so I decided to install it to the PC where I’m having problem on opening the database file.
|Unrecognized Database Format BIR 2305|
How I Solved Unrecognized Database Format .accdb File
If you installed MS Office with default installation you need to update it with its service pack, for Access 2007 they already have SP2 and SP3 released. You can install one of them only to solve your problem regarding unrecognized database format problem. Just download the file at official Microsoft website, make sure to use administrator account during installation. You can also use Windows Update to solve this problem in case you don’t want to do a manual update.