Prior to upgrading Nexus Personal, you will need to uninstall the existing versions of the program by following these steps:
Locate your computer’s taskbar.
Open Programs and Functions.
Look for the Nexus Personal program and then uninstall it.
You also need to delete the Personal file, which can be found at C:\Program Files(x86)\Personal (if you cannot delete the folder, delete as many files as you can).
You will also need to delete the Personal file from AppData / Roaming profile (C:\Users\user_name\AppData\Roaming\Personal).