How do I remotely log into multiple computers?

Question

I have a task to write an server application that will log into multiple other computers on the same network. The other computers will be at the startup screen and instead of having to input the user name and password at each computer, the application should do this.

I have done some research and found the LogonUser() function. But msdn states that this function attempts to log a user on to the local computer.

Does anyone know if this is possible? And if so, can you give me some direct?

Do i need to create a service that runs on the client PCs?

Thanks for any help.