Over past 10 years, the related databases created in Access 2003 have evolved and been run in Access 2010 but remain in *.mdb format. Does anyone know why the 'file open' reaction time is getting slower* compared to open time in 2003? Compacting is done daily, Windows 10 is being used. We are considering upgrading to Access 2013, but have some clients using Access 2003 so must keep the mdb format. Not using Web database at all. Is the multi-user concept and not having passwords significant whatsoever?