We always recommend exercising caution when upgrading to a new OS, especially if you have any crucial deadlines approaching. Please make sure you have your system completely backed up and give yourself time for troubleshooting any issues.
To protect your activations while you make changes to your OS or hard drive, you can Deactivate your copy of Photo Mechanic® before starting the OS upgrade.
From the Help menu, go to Licensing: Deactivate this computer.
You can reactivate your software after you are finished upgrading. Just choose "Register" when you open the software and then enter your License Key.