How can I avoid windows being rearranged when I use my KVM switch?

Question

I have bought a KVM switch. It works fine, except that when I use the switch, it seems that the computer I'm switching from loses the monitor (as in: Windows thinks that the monitor has been disconnected). This causes all of the application windows that were on the "lost" monitor to relocate onto another monitor.

This is not desirable. I would like Windows to either think that the monitor is still there, or in any case not automatically move the application windows around. I am happy for the windows not to be visible while I am switched away from that computer; when I switch back, I would like them to be where I left them.

However, I will sometimes be genuinely reconfiguring the monitors connected to a machine (for example, because I take my laptop from home into the office). On these occasions, it is desirable that the windows be rearranged - either they should be rearranged automatically, or I should be able to send a signal (e.g. a combination of keys on the keyboard) to trigger a rearrangement.

How can I fix this problem? Either of the following outcomes is acceptable to me:

1. Some sort of configuration change (whether in Windows or on the KVM) so that using the switch function of the KVM does not make Windows (running on the computer being switched from) think that the monitor has gone away.

2. A configuration change to Windows that will allow me to disable automatic rearrangement of application windows, but with the proviso that I want to be able to easily invoke the rearrangement (that by default happens automatically) on a manual basis.

The computers I'm using are all running Windows 10.

The KVM switch I have is the Greathtek GHT-S7210P (DisplayPort model).

The switch comes with minimal printed documentation. I have looked online for documentation. I was able to locate a manual for what appears to be a model from the same manufacturer and similar to the one I have, but with HDMI ports rather than DisplayPort. The manual does not mention this issue, nor any configuration options other than what is physically present on the device.

Answer 1

You have to use "special" KVM switch which has some reference to "EDID" like "EDID emulation", "EDID simulation", "EDID passthrough", etc. Low end KVMs with "EDID" will create a virtual monitor for your PC to trick it into thinking it is still connected. More expensive one will passthrough information from your real monitor to your PC. You can check following products on amazon - ASIN ‏ : ‎ B0B2ZV1YQS and B081251PBW

Answer 2

This has been plaguing me since I purchased new monitors and a new dual monitor KVM. I have tried clearing my graphics driver configuration registry settings and even purchased a couple of inline EDID adapters*, but the problem remained. I have found a silly workaround, however.

Before I select the switch on my KVM, I hit the windows key + D (which hides all the windows). When I switch back, I hit the windows key + D again, and my windows are where I had placed them. Note, this can sometimes re-arrange your windows even without the KVM switch, but it's better than throwing them all to the primary monitor.

*_{Perhaps there are some that would solve this problem, but the two models I tried messed up the monitor recognition and the resolution was incorrect while inline, and I was unable to change it.}

Update: I did finally find a dual port KVM with emulation that works. This solved several inconveniences.

Second Update: My setup changed a bit so I tried to update my KVM. I had no luck whatsoever with DisplayPort KVMs. I bought and returned no less than five separate KVMs, with varying degrees of success, but none that would make the switch successfully. In the end, my new monitors will switch if the signal goes out, so I've been using that to swap, usually putting one to sleep with the other powered on and my monitors just switch inputs. I still use one of my older KVMs, but just for KM. Not ideal, but functional. Good luck finding a KVM that works!

Answer 3

Currently, for DisplayPort KVM switches, only the DDM-class KVM switches can provide full-bus EDID emulation and EDID feeding to all connected systems.

In case, you're looking for a DisplayPort KVM switch (especially for DisplayPort 1.4), pick the DP 1.4 DDM-class KVM switch for your setup.

Answer 4

I've been hunting around for solutions to this, and found MikeTheTech's Virtual Display Driver at:

https://github.com/itsmikethetech/Virtual-Display-Driver

with the installation tutorial here:

https://www.youtube.com/watch?v=byfBWDnToYk

After installing the virtual display, I set it up to be identical to my KVM monitor. Same resolution, refresh rate, set it as my main monitor, then mirrored it onto my physical monitor.

Now when my KVM 'disconnects' my monitor, windows keeps all my applications in the same position.

When you're disconnecting the monitor for real, you'd have to disable the emulated monitor in Device Manager, then windows will reorganize your open windows.

Answer 5

For people who don't have a KVM with EDID emulation/passthrough. I have found a solution that can work in Windows. Using Powertoys with fancy zones this allows you to keep the windows locked to the specific screen/zone it's assigned to despite the screen connecting and disconnecting.

Powertoys store link: https://apps.microsoft.com/detail/xp89dcgq3k6vld?hl=en-gb&gl=IE

documentation for Fancyzones: https://learn.microsoft.com/en-us/windows/powertoys/fancyzones

setting needed to keep the windows locked to a zone:

"Keep windows in their zones when the screen resolution or work area changes"

Answer 6

If this is office work and 1080p then an easy reliable hack is to step back a decade or two: use a VGA-based KVM. It's possible you can get higher resolution but for VGA that's not guaranteed.

You will need DP (or hdmi) to VGA adapters. They are passive, cheap and inline. Your monitor must support the VGA input.

Answer 7

At some point, Microsoft seems to have added some new options to the System > Display settings to control this. These might only be present in recent builds of Windows 11 (I'm on 24H2).

After expanding the "Multiple displays" section, there are two checkboxes concerning window behavior when monitors are connected or disconnected. They are checked by default, but after unchecking these, I haven't had any more issues with windows moving around on me when using my KVM switch.