What do I need to backup

Pro 60120 unit with Mach 4

I want to do a clean reboot of the control PC (windows, cnc software… everything)

What do I need to backup? (config files etc.)

You can backup the entire Mach4 directory by just copying it to a thumb drive.

Setup your new PC, install Mach 4 fresh, delete the installation fresh Mach 4 folder and copy yours in and you should be good to go