This is not specific to Windows 10 or any Outlook version but a general best practice for Outlook.
There are many known issues caused by having a virus scanner integrated with Outlook.
There is no need to install this afterwards as Windows 10 has the features of Microsoft Security Essentials built-in in the form of Windows Security (which replaced Windows Defender).
Windows 7 Start users can upgrade to Windows 10 Home.
Programs, files and settings will then be migrated automatically to Windows 10 and after upgrading you can directly logon to Windows 10 and start Outlook with all its files and settings in place; just like you left it in Windows 7 or Windows 8.
However, for either upgrade, there are still a couple of attention points before you start.
This guide contains not only upgrade preparation and troubleshooting steps but also various tips about the changes that you could encounter involving Outlook after upgrading to Windows 10.
This will increase the speed of the upgrade, its chance of success and decrease the chance of ending up with broken applications or other troubleshooting requirements.