A family of Microsoft relational database management systems designed for ease of use.
A2007 and A2010 are much starchier about security than previous versions. Anything with VBA code (including some functions called from queries) will be flagged as "UNSAFE" (and will not run) unless the database is "signed" by a trusted publisher, or unless you use the Trust Center to mark the folder containing the database as a trusted location.
To do so, click the Office medallion in the upper left of the screen; select the "Access Options" button; choose the Trust Center from the menu; select "Trust Center Settings" and then "Trusted Locations". Add the path to your database to the trusted list and check the "Allow Trusted Locations on my network" (even though it says "not recommended").