I have renamed the freshly installed directory something like Mach3fresh then copied the folder from the defunct computer to the new computer's drive C. That way if there is a corrupt file or two in the older version you have something to replace it with from the fresh install. I also regularly copy the working Mach3 folder onto something other than the working hard drive to preserve any changes that have been made in case the working folder gets scrambled. It doesn't take much space up on a USB stick. The thought of having to reconfigure everything from scratch is worrisome.

Most recently I copied the folder onto a different machine as the old one was starting to play up, dodgy USB ports on the motherboard was one problem it had. It caused no issues to just copy everything onto a new drive that had had a fresh install carried out on it first.

Martin C