When you try to install a large Microsoft Windows Installer (.msi) package or a large Microsoft Windows Installer patch (.msp) package on a computer that is running Microsoft Windows Server 2003 or Microsoft Windows XP, you receive the following error message: Error 1718.

File File Name was rejected by digital signature policy.

trouble updating service pack 3-45trouble updating service pack 3-67trouble updating service pack 3-83

However for an Exchange 2010 Database Availability Group the upgrade process can be performed with no downtime following the normal process of moving active databases off DAG members while they are being updated.

You can use the standard process as demonstrated here: However, be aware that once a database has been made active on an Exchange 2010 SP3 member of the DAG, it can't be made active on a pre-SP3 DAG member again.

Each of my test lab servers took between 20 and 30 minutes to upgrade, but your performance will no doubt vary.

Paul is a Microsoft MVP for Office Servers and Services.

MSI (s) (90: C8) [:792]: Note: 1: 2262 2: Error 3: -2147287038 MSI (s) (90: C8) [:792]: Transforming table Error.

MSI (s) (90: C8) [:792]: Note: 1: 2262 2: Error 3: -2147287038 MSI (s) (90: C8) [:807]: Transforming table Error. MSI (s) (90: C8) [:807]: Note: 1: 2262 2: Error 3: -2147287038 MSI (s) (90: C8) [:807]: Transforming table Error.

MSI (s) (90: C8) [:776]: Note: 1: 1729 MSI (s) (90: C8) [:776]: Transforming table Error.

MSI (s) (90: C8) [:776]: Note: 1: 2262 2: Error 3: -2147287038 MSI (s) (90: C8) [:792]: Transforming table Error. MSI (s) (90: C8) [:792]: Note: 1: 2262 2: Error 3: -2147287038 MSI (s) (90: C8) [:792]: Transforming table Error.

This means that you will need to roll through your entire DAG upgrading to Service Pack 3 to retain the full availability resilience your DAG is designed to provide.

For Hub Transport, Edge Transport, and Unified Messaging servers there are no special steps required other than to manage your upgrades in a way that aligns with whatever high availability you have in place or those server roles.

This seemed to be a major issue to me until I performed the upgrade in my test lab.