Is it possible to take the VGA signal from one laptop and send it into a second laptop?
Here are the details:
Our church uses vMix to manage our church service. We have a VGA cable on the stage for guest
speakers. That cable goes to a VGA A/B switch in the control booth. We have a second laptop
in the control booth that we use for PowerPoints that uses NDI into the desktop computer that
has vMix on it. The desktop has a VGA output that goes to the A/B switch. We have several guest
speakers that bring their own laptops that they place on the stage and connect to the VGA cable
there. We would like to be able to send the stage computer output to the control booth laptop so
we can send it to vMix. Right not we are only able to send output either from the desktop computer OR the
stage computer via the A/B switch.

I thought of using Desktop Capture, but that means that we would have to copy and install onto
the guest speaker's laptop. We usually don't have the time to do that and some times they will
bring an Apple laptop. The other thing that might work is to use a VGA to USB converter, but not
even sure is such a thing exists.

Any suggestions?

I can report very good experiences with the AV.IO. Driverless, works flawless.