Hello,
You can package up your profile by going to Help>Support>Package Current Profile. This bundles up your settings including macros and screens. Once you have Mach4 installed on your new computer, use the 'Import' option in the Mach4 Loader to unpackage the profile. You can update the PC ID on your license by going to 'Manage My Licenses' at machsupport.com. Copy the PC ID from the Help>About menu in Mach4 (on the new computer) and paste it into the PC ID field on the licensing page. Click 'Add' and a new license will be generated with that PC ID. You'll receive an email with a link to download it.
-Bryanna