I think you're asking about the .laccdb file. If so, first off I have to explain that you don't want to open it or modify it in any way. It is a temporary file that takes care of itself (opening, then closing and deleting itself) when you open an Access .accdb file properly. Yes, there are times when the .laccdb file persists even after you've opened and closed an Access .accdb file properly. If that happens, so problem, just delete it. It will recreate itself when you open the .accdb Access database file again. But to directly answer your question, find the .laccdb file in Windows Explorer. Right-click, Show More Options, Properties. On the General tab, Change, and you can then find the application that you want to open the file with that specific extension. But again -- you should not ever need to do this. Please watch the KZfaq again in its entirety to have a sense of how the .laccdb file works and why you really never need to directly interact with it.