Update SQL Server 2016 from RTM to SP1 I have SQL Server 2016 RTM installed and would like to update it to SP1. When I run an SP1 cumulative update, it fails because there is nothing to update. Presumably this is because it needs SP1 to be installed first. When I run the SP1 installer, it wants to create a new instance.

How can I update an existing instance from RTM to SP1 without having to uninstall and reinstall the instance?
It sounds like you've downloaded a copy of the full SQL Server 2016 (with SP1) installer. (Microsoft often distributes the installer with the latest service pack built in.)

Instead, download Service Pack 1 by itself, then apply the latest cumulative update.