How to configure multiple monitors for remote desktop use
A remote desktop workstation may require specific configurations for the local hardware, including options to set up multiple monitors on an RDP desktop.
IT teams need to support remote desktop users with whatever peripheral device setup and troubleshooting they need, including multiple monitors.
Users in the financial sector and healthcare -- among many other industries -- are especially used to multiple monitor configurations, putting pressure on IT to adjust the settings to meet user needs. The challenge is getting remote desktops to detect and interact with local hardware when the desktop isn't running locally. Further, multiple monitors are turned off by default for remote desktops.
A key factor here is that enabling multiple monitors in Microsoft Remote Desktop Protocol (RDP) is an option the end user needs to enable on their Windows or Mac device. As an administrator, it is not something you can configure on the server side. As such, it might be a good idea to write up a good user instruction manual -- feel free to base it off these instructions.
Before IT embarks on this process, it's important to keep the limitations of multiple monitor RDP in mind. While it will be more than enough to have two medium resolution monitors, RDP users are limited to a maximum of 16 displays with a maximum resolution of 8192 x 8192. IT can also connect via RDP to a virtual desktop on a virtual server with multiple monitors. This will simply create a virtual desktop on the end user's monitors.
Set up multiple monitors on a remote desktop session
On Windows systems, there are three ways to use multiple monitors with RDP. As an IT administrator or user, you can follow these steps to accomplish the task.
First, click on the search icon in the Windows start bar and search for "MSTSC/ MULTIMON." This will start up the RDP client in a multi-monitor configuration. From here, you can enter the server address, and it will automatically connect to the server full screen on all your monitors.
The other method to start a session with multiple monitors is by launching the Remote Desktop Connection agent the usual way from the start menu.
Then, go to the Display tab and select Use all my monitors for the remote session (Figure 1).
The final method to configure multiple monitors in Windows RDP is with an RDP file. This approach is more advanced.
You can save the connection setting of the RDP session in the general tab of the RDP client. These settings will then be saved in an RDP file. You can edit this file within the client, or simply with the Notepad app.
After opening the RDP file in Notepad, you can change multiple options. But the one that configures multiple monitors is called use multimon:i:1. The number 1 means the option is enabled and 0 means the option is not enabled (Figure 2).
For macOS, there are two ways to enable multiple monitor support. The first way is to edit the RDP file with Text Editor in the same way as editing the RDP file on Windows. For macOS, the same setting for multiple monitor support is called usemultimon:i:1, where 1 means enabled and 0 means disabled.
The other way to enable the option in macOS is in the options of the RDP connection in the Microsoft RDP client. In the Display options, there is an option to enable Use all monitors (Figure 3).
It's also good to mention how to enable multiple monitor support on RDP within Igel OS. Igel OS is one of the most popular thin client OSes next to Windows. Within Igel OS, when setting up an RDP session, there is an option called True Multimonitor support. Enabling this option will allow multiple monitor support within Igel OS (Figure 4).
Other options to fine-tune UX on multi-monitor RDP sessions
Enabling multi-monitor access on a remote desktop is the first and most essential step to providing good UX, but IT teams need to account for several other factors.
The 'use selected monitors' option in RDP
An RDP session will automatically detect the setting to use multiple monitors and run all available monitors. However, this may not be the best user experience in certain situations. Consider an example where you have three monitors and want to use local apps on monitor one and use monitors two and three for an RDP session. This can be configured with the selected monitor's option.
Running the command MSTSC /L will output the available monitors on the system and show the monitor IDs. In this example, the monitor hosting local apps has ID 0, and the other two monitors have ID 1 and 2. With this information, you can edit the RDP file by adding the selectedmonitors:s: option. The correct configuration in this example would be selectedmonitors:s:1,2 together with use multimon:i:1.
Using published applications on multiple monitors
Published applications are applications that are loaded from an RDP session, but instead of showing the full remote desktop, the end user will only see the image of the chosen application. This should automatically work on multiple monitor setups. In addition, the end user can drag and drop the application screen to any connected monitor they like.
Using published apps also gives more freedom of use on the end user's device because it will appear that the remote applications are running exactly the same as any local applications making switching between these applications feel natural and normal. This is an excellent alternative for users who only need hosted applications and can run a native desktop for work. The method is especially helpful if the end user connects from a capable Windows device that also hosts local applications.
