Hi Ts, I guess we are not being very helpful but we don't have a lot of information to work from!
First, I have recently upgraded to using Mach 3 under Windows 10 using CNC Drive components and it was fairly painless. I therefore think that Win11 should work. So hopefully there is light at the end of the tunnel for you!
From what you say you have a CNC Drive Ethernet motion controller (that is, the connection to your laptop is via Ethernet). Please could you tell us which driver you have? It might help to look at their website at
http://cncdrive.com/products.html - it's probably either a UC300ETH or UC400ETH.
I would guess that you have a modern laptop that doesn't have an integral Ethernet port - this is quite common these days since the Ethernet connector is too high for thin laptops. So I would guess that you have USB-C ports, which are quite fast enough to support Ethernet up to 1 Gbps, and a USB-Ethernet "dongle". Is this correct? I can't see why this should give any problems, if it supports general Ethernet connections up to 1 Gbps I doubt that Mach 3 can throw anything it can't handle. (I have a Huawei Matebook Pro that is 2 years old and it doesn't have any Ethernet ports either, though actually I have a mini Win10 machine for the CNC.)
Now, where did the Mach3 software you have come from? As supplied (e.g. on a CD or downloaded from the NFS website), it has a "plugin" that converts commands from the main program into pulses to drive the stepper drives and output these through the parallel port. However modern PCs, especially laptops, don't have the old-fashioned 25-pin parallel ports; and they aren't supported under modern Windows either. So you need a separate motion controller (such as the one you have from CNCDrive) and a different Mach3 plug-in that outputs the commands from the main program over Ethernet (or, in a different version, USB) to the motion controller.
You can download the required plugin free from the CNCDrive website and if it's like the UC100 one it can auto-install into the right place in Mach. There is good documentation on this on the CNCDrive website.
So I suggest you check which moption controller you have and download the plugin and documentation, and follow the instructions to install it. You should then find when you launch Mach3 that it puts up a screen where you choose which plugin to use, the Ethernet one or parallel port, you choose the first, then things should start to work.
Try these things, then come back and tell us how you get on and whether you need further help.
John.