If you are upgrading from a version earlier than Outlook 2007 Service Pack 2, then several extensive file structure changes to the pst-file are being made which could take a lot of time (especially with a large pst-file).
Upgrading from a later version usually goes a lot quicker.
You’ll find the setting under: Computer Configuration-If you were using Outlook Business Contact Manager (BCM) with Outlook, then you’ll no longer be able to use it with Office 2016.
BCM will not be updated for Office 2016 compatibility.
For more information see: Should I install the 32-bit or 64-bit version of Office/Outlook?
Note: Even when you are using the 32-bit edition of Office 2016, some add-ins might not be compatible yet with Office 2016.
If the update isn’t being offered to you yet, go to: File-There is no need to uninstall your current Office 365 installation first.
Now that your machine has been prepared, you can run the installer to install Office 2016.
If the 32-bit edition is what you want (again; this is recommended), then just follow the setup instructions and move to the next section in this guide.
If you want to install the 64-bit edition, keep reading…In order to install the 64-bit edition of Office 2016, you’ll first need to uninstall all 32-bit Office applications, including older versions.
If any such application is still installed, you will not be able to install the 64-bit edition of Office.
It of course never hurts to make a backup of your Outlook data first.
If you are having difficulties removing your current version of Office via Control Panel, you can use the Fix It from the Microsoft KB article below which matches with the version that you wish to uninstall: When you are currently using an Office 365 installation of Office 2013, then upgrading to Office 2016 is going to be really easy as it will be offered as a regular update.
When you are currently using Outlook 2013 as part of an Office 365 subscription, you can postpose the automatic upgrade to Office 2016 for up to a year after its release by setting a Registry value.