Windows 7 Outlook stopped working

27th October 2021

Microsoft has quietly dropped support for an older TLS version, Windows 7 pre-dates the TLS series so it needs to be installed as a windows update and I have had to add a registry key to get these systems working.

A lot of info here https://docs.microsoft.com/en-us/mem/configmgr/core/plan-design/security/enable-tls-1-2-client

Outlook doesn’t require .NET framework so ignore that in the article above

The patch is available from Microsoft here https://www.catalog.update.microsoft.com/search.aspx?q=kb3140245

The registry entry I am using is below:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\WinHttp]
“DefaultSecureProtocols”=dword:00000aa0