I have been using Mouse without Borders , a program that allows you to make a virtual KVM between machines for some time at home and it is awesome. You can use one set of keybard and mouse among various (windows) machines including clipboard and copy and paste. If you haven’t tried it, I would highly recommend it.
However lately I could not connect between two machines and kept getting the error: “Only one usage of each socket address”. To the point where it was unusable and was pretty annoying. I looked online at their site but nothing jumped out. BTW, I was seeing this only on one machine (running Windows 10) and not the other one (also running Windows 10 but an inner ring of the Creators Update - essentially the next version of Windows).
What I understand the issue to be is that Windows is running out of ports and where programs that use a port for a short time, it won’t matter much, in this case the port is always going to be used.
The solution that seems to be working for me is quite simple - we increase the number of ports available to Windows. This is quite simple and to do this if you run an elevated command prompt and copy and paste the following command:
netsh int ipv4 set dynamicport tcp start=1025 num=64511
And if you are not sure on how to get the elevated command prompt - easiest way to do that is press WinKey + X, and from the menu select Command Prompt (Admin) as shown below.