TL;DR

Make sure SSL is off and recent TLS is on.

If you resume a very old Windows system and decide to give it a try, you might have that kind of feeling of how people lived in the past. Well, a few years ago, at least, which almost surely includes you as a probably-not-so-young reader of this blog (yes, I’m looking at you, future me!).

You try to start common Microsoft Office programs with an account that has the right licenses and… nothing, they will not let you in. Teams refuses to comply, suggesting to Retry, giving a cryptic (and often changing) error code that seems like a digest and telling you there is a better way to start Teams…, only there’s no Force in this universe. Outlook may or may not start, but even then it refuses to connect, sometimes after having asked your credentials for 10 times in a row (you throw in the towel because Einstein would consider you a stupid otherwise, but Outlook won anyway). OneDrive happily stays there wheeling. Excel might have a Word or two of complaint, and still you can’t get the PowerPoint.

OK, those were very, very bad puns.

Out of the gazillion things that might have gone wrong, it might depend on the SSL/TLS settings.

Want to check? Try this:

• Start menu (or whatever they call it today), search for Internet Options and open it
• go to the Advanced tab
• scroll down until you see a list of checkboxes that name SSL and TLS
• check TLS 1.2 and everything above (if present)
• for good measure, uncheck everything below.

The last step might lose you some backwards compatibility, which you can later restore in case of extreme need (still, consider the deprecation).

Every Windows release will have it owns specific sub-list, like e.g. TLS 1.3 might be missing, included with a notice that it’s experimental, or just included. I think it’s fair to check it if present, anyway.

I hope this will help you get back in Office, cheers!