Use Dual Monitor with VirtualBox virtual machine
You need to carry out these steps to enable dual monitor for VirtualBox virtual machine- To get started, you need to install the Guest Additions CD image. There is no need to download anything else since your VirtualBox installation comes with this package. By default, it doesn’t install the package, but this is required to get lag-free user experience. To install Guest Additions CD image, open VirtualBox, start the guest OS and make sure you are logged into the system. After that, go to Devices > Install Guest Additions CD image. Alternatively, you can press right Ctrl + D.
You should get a popup on your screen. Follow the screen instructions to finish the installation. After that, you need to add the second monitor to your virtual machine. For that, open the VirtualBox > select the virtual machine > click the Settings button. Then, go to the Display section and make sure you are in the Screen tab. From here, you need to assign the maximum video memory to your virtual machine. For that, use the Video Memory bar to provide the maximum available video memory. Secondly, select two (2) in the Monitor Count box.
These two settings are mandatory. However, if you want better performance, you can select the Enable 3D Acceleration checkbox. After making all the changes, click the OK button to save. Now start your virtual machine and press Host + F buttons together. By default, the right Ctrl is the Host button. After that, you have to assign a virtual screen to a host screen. For that, go to View > Virtual Screen 1 > Use Host Screen 1.
Similarly, go to View > Virtual Screen 2 > Use Host Screen 2. Now you can find the virtual machine on both monitors. Also, if you want, you can use Host Screen 2 for Virtual Screen 1 as well. I hope this simple solution will be helpful for you. Read next: How to use dual monitor with VMware virtual machine.