Hi Mike,
dude1 is right, under View menu Load Screen and choose wx4.set.
If you like the screen set you need to copy it and rename it, something like Mikeswx4.set. Then can alter and edit and add functions
to it in any way you like. When you get a later release of Mach4, they come out every few months, it will include a new wx4.set.
If you've edited or changed your existing wx4,set without renaming it all your edits/changes will be overwritten and lost.
I've had that happen and its pretty frustrating.
While on the subject its worthwhile to on occasion to save all your customisations and preferred settings by using Help/Support/Package Current Profile
and give it a distinct name and maybe a date. If you screw up bigtime you can go back and retrieve it.
Craig