Unanswered: Hi knights, do you get error "Invalid Instance" ?
I create 2 instances SQL Server in the same server using port 1433, unluckily when i connect they from the remote pc, it doesn't connect and alert "Invalid Instance". How can i use many instances? And what special when i replicate them?
So it isn't the remote clients as you originally posted? Did the local clients work and then stop, or never work at all? Can you connect from any machine except the server itself? Can you connect to the instances on the server itself?
I suspect that the problem may be because you've set up two instances to use the same TCP port. If you check the KB article I cited, each instance normally has its own port, and the port usages are arbitrated by port 1434. Only the default (unnamed) instance of SQL Server should use port 1433.
I'd suggest that you try to reconfigure the server that way to see if it works.