How to create monitor for specific windows service?

Careful with this one. Yes it works, but you only need it, if there is no Windows service. Windows services are collected by the agent by default, you just need to tell checkmk, that it should monitor a specific service as outlined by @jan.filo.
An enforced service is only necessary, if you want to monitor a process that might vanish, or the other way around: A service that should not be there.