QUESTION I have two PCs connected to a single monitor via a VGA switch and I now need to connect a 3rd PC in the same way. Each PC has their own keyboard and mouse, so they only need to share the monitor. I have searched the net for an adapter with one female and two male connections to 'split' the cable from the monitor to the second PC in order to gain a third connection. However, I can only find versions with two male to one female connector – which would be for connection two monitors to a single PC. Can you help me with my setup?
HELPROOM ANSWER Because VGA connections are analogue in nature, you'll want to maintain a high-quality connection without any possible interference from other devices, so we would recommend upgrading your VGA switch to a version with more than two ports rather than trying to cobble together a third connection by splitting a cable between two PCs. You would also presumably want a way to choose which of your PCs is using the monitor without having to turn off the PCs which aren't in use. This will require a switch selector of some kind.
A quick search on eBay for "VGA switch" reveals a few four-way VGA switch boxes are available for well under £20, so we would recommend replacing your existing VGA switch with a version which can accommodate all three displays. Although you say you have a keyboard and mouse for each PC, you will also find full KVM switches available for the same sort of price which you can use to perform the same function. Just keep your keyboards and mice plugged directly into their respective PCs as normal and use the KVM switch to switch the video only. Before you buy one, check the specifications and ensure that the maximum supported video resolution and refresh rate suits your needs.