Online updates are important but may take time. If preferred, you can stop update checks, especially on client machines, by manually changing the update service settings. Keep the online update enabled on the main/server computer to receive notifications. Login speed on the server is not affected, so there's no need to disable it. To skip the check for online updates:
At the client computers, open Control Panel, Administrative Tools, Services.
In Services, look for Access UBS Update Service.
Right-click this and select Properties.
Change Automatic to Manual
Stop the service.
If there is an online update available at the server computer, you need to Start the Access UBS Update Service at the client computers to run the update.