There are few things you will want to know:
1. MasterCook 2020 will FAIL to install if My MasterCook Manager version 15 is running in the background on your computer. The version 2020 installer is not able to force it to shut down. However, you can simply restart your computer. Do NOT use MasterCook 15. Then install version 2020. It will replace the version 15 with its own version. (It can't do that if the version 15 one is running in the background of the computer.)
2. You should have a recent backup copy of your files for the existing version of MasterCook you are using. See these instructions: https://support.mastercook.com/hc/en-us/articles/216889106 DEFINITELY DO THIS BEFORE YOU DOWNLOAD OR INSTALL VERSION 2020.
3. If you have ingredients with red circles in the recipe edit screen, those ingredients are linked to the older version (15 or older) that you set. You will need to reset those links. Just right click on one and select Reset Ingredient Nutrition from the bottom of the command list that appears. Then version 2020 will be able to use its own. MasterCook does not modify or change your recipes, so you have to reset your ingredient links so version 2020 can use its own. See this article for a list of ingredients included in MasterCook 2020.
4. MasterCook 2020 does not pre-install the cookbooks. Many people do not want them or use them. However, MasterCook 2020 can certainly use all of the cookbooks from any previous version. We also have free cookbooks available at MasterCook.com. See What To Fix For Dinner. We will be adding more free cookbooks to MasterCook.com. We will even work on adding the cookbooks that have been included in older versions of MasterCook for those that don't have the older versions.
5. If you have customized or added ingredients to the Ingredient List in a previous version of MasterCook, you can contact us in MasterCook Support and email us your MC Ingredients.ing file. We can convert your ingredients into version 2020 for you and send you back a merged MC Ingredients.ing file.