Open Mach and look at your main page lower right and you will see the name of the profile you are using. Close Mach and go to the Mach3 folder and look for a file of that name with an xml extension, copy it to another location. Also save the brains folder if you have any made , the macro folder of the profile you are using, the plugins folder if you are using any and lastly if using a custom screenset save it and any images. Oh one more, your licence file, its called Mach1Lic.dat and is in the Mach3 folder.
Once you have all of that backed up then you will have no problems upgrading as if anything goes wrong its just a case of copying the files back.
To actually upgrade its as simple as starting the exe you downloaded and letting it install.
However you never answered the questions I asked, for the spindle speed to be seen by Mach these conditions need to be met.
Hood