Open the Start Menu/Run command from the EPO server and type \\hostname\admin$ (hostname being the system's hostname that you are trying to deploy to)
You will most likely receive some kind of error because the admin$ share is inaccessible, either completely or because of the credentials used. Please follow this kb for prerequisites for deploying Agents:
Thank you for your help mmcgary.
Problem was Windows Firewall, now deployment runs.
But there is a strange thing: I get an error "Failed to access remote system registry, system error: The network path was not found", but in fact deployment ends succesfully and I can manage agent without problems. Will I have problems with that?
No that is a common error during successful deployment believe it or not. I don't know why exactly since the remote registry service is indeed required.
Thank you very much