There is just one question when you want to create a new ServiceTier for NAV 2009:

How exactly was the command again?

This is what you have into Command line to create a new service:

sc create NewServiceTier start=demand binPath="\E:\All Clients NAV\60 R2\Build 33346\Services\NewService\Microsoft.Dynamics.NAV.Server.exe"\"

After adding the service, you can change the login-account using the local services window.

The Service can be removed again using this command:

sc delete NewServiceTier