We assume that you already configured System and IIS modules.
Go to Settings > Virtual Servers
Click Add Virtual Server button
Give server a name, put comments (optional) and click Add Server
Edit Virtual Server page will appear on the screen. Click Add Services button to open list of services added in your MSPControl
Select System and IIS (Web Sites in example below) services and click Add Selected button. If you didn't add System service yet, do it and then come back to this page again. Ensure that System service added to your Web Hosting server and not to any other.
Scroll down to Update button and click it
Now your Virtual Server ready for next step - Hosting Plan creation