Hi Roger,
In order to help you connect your monitors to your Window 10 computer, you may consider the steps in the helpful Forum Article posted by Andre Da Costa MVP. The article focuses on configuring a dual monitor setup as well as how to add and use a second monitor. This article has been useful to a lot of Community members who had the same concern. Click the link to begin your troubleshooting procedure.
How to add multiple monitors to your Windows 10 PC
Let us know the result for us to help you further.
Regards.