Okay, if you highlighted "Path" and then did the Edit, then you were indeed on the right screen.
Win10 must be showing you a nicer format/version for editing the individual paths...so, I think if you did what you posted in the images above and hit "OK" on the last few screens (i.e., you'll want to get back to the "System Properties" window).
Then, you should be able to launch a Windows Command Prompt and see the fruits of your efforts--i.e., typing "PATH" (without quotes) should show you that your PATH environment variable now has your new c:\jfalls63utils directory on it.
You can change that name to be whatever you want, of course. Also, you'll place/host your utilities in that folder and you should be able to reference "fastboot.exe" (or just "fastboot") without having to copy your files into the folder like you did before or giving a full-blown pathname (i.e., you can just type "fastboot.exe" instead of the full "c:\jfalls63utils\fastboot.exe" path).