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.

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

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.