Windows – How to emulate PrintScreen key in VirtualBox on a Mac host

While there are some Host Key shortcuts that activate certain VirtualBox functions (eg, Host Key+P which pauses the Guest), I don't know of any way to configure VirtualBox to send Host Key shortcuts to the Host OS.

However, since VirtualBox has an open source edition, it may be possible to modify the source code to add this feature. You can access the VirtualBox source code at the Download link.

In the meantime, you can use the Host Key to release the keyboard from the VirtualBox Guest's control. By default the Host Key is set to Right Ctrl. You can see the current Host Key in the VM window:

Just press the Host Key once to release the keyboard capture. After that, your Host OS will see your keypresses. So here's your workflow:

1. Press and release the Host Key. Your Guest OS no longer captures keypresses.
2. Press Ctrl+Alt+(Arrow key) to switch workspaces, or any other keys you want to send to the Host OS.

You should really consider switching from NAT to bridged mode. This way both "systems" will be on the same network. When you run with NAT it subnets the network and your VM effectively exists in another network. In order to make it work with NAT you will need to configure (through configuration files, not GUI options) the NAT routing to open connections/ports between the networks, and also setup routing tables.

If you set bridged mode, the VM requests the IP from the same router that your host does, instead of from the VM system on the host. In turn it will be as easy as just going to the IP of your host.