I created a simple database in Access 2003 on my PC and opened it with Access 2010 Runtime on my laptop as a test. The database opened ok but with a security warning because the database did not have a certificate. I rebuilt the database in 2010 format and then signed and packaged it using a certificate I produced in Office Tools. I opened this on my laptop using Access Runtime and got the same security warning. How do I produce a database which can be opened with Runtime without the warning coming up? Or to put it another way, is there anyway I can get Access Runtime to recognise my certificate? If not then signing and packaging a database seems a waste of time.