Office Click-to-Run Installations:
Same Bitness (32-bit Office running on 32-bit Windows or 64-bit Office running on 64-bit Windows):
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\ClickToRun\REGISTRY\MACHINE\Software\Microsoft\Office\x.0\Outlook\Security
Different Bitness (32-bit Office running on 64-bit Windows):
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\ClickToRun\REGISTRY\MACHINE\Software\Wow6432Node\Microsoft\Office\x.0\Outlook\Security
Office MSI-Based installations:
Different Bitness (32-bit Office running on 64-bit Windows):
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Office\x.0\Outlook\Security
Same bitness (32-bit Office running on 32-bit Windows or 64-bit Office running on 64-bit Windows):
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\x.0\Outlook\Security
NoteThe x.0 placeholder represents your version of Office (16.0 = Office 2016, 15.0 = Office 2013)
DWORD: ObjectModelGuard
Values:
0 = Warn me about suspicious activity when my antivirus software is inactive or out-of-date (recommended)
1 = Always warn me about suspicious activity
2 = Never warn me about suspicious activity (not recommended)