Microsoft Access - AeXTreeCtrlLib.dll error

Problem:

At some point, when the Microsoft Access 2007 database file (ending in .accdb) was moved from a Windows XP system to a Windows Vista and Windows 7 system, upon startup, an error about a missing DLL named AeXTreeCtrlLib.dll.

Solution:

Not sure what the cause was or how to fix it. The workaround I came up with was to create a brand new database and then import the tables, queries, forms, and reports from the old broken database. Wala! Magic! Fixed, at least seems to be.

Crazy!