Issue: Unable to sign in to any Microsoft Office desktop applications (Word, OneNote) on Windows 11. Receiving error code 0x800704cf on every sign-in attempt. What I've tried: Reset network stack (netsh winsock reset, ip reset) Cleared Windows Credentials Manager Reinstalled Microsoft Office Ran SFC scan — no integrity violations found Deleted Office Identity registry key (HKCU\Software\Microsoft\Office\16.0\Common\Identity) Ran Microsoft SaRA tool — no fix found Test-NetConnection to login.microsoftonline.com port 443 — TcpTestSucceeded: True Can sign in via browser at office.com without issues Adding a new Windows user account also fails with "Something went wrong" Conclusion: Network connectivity is confirmed working. Issue appears to be with Windows authentication system (WAM), not Office itself or network. Browser-based Office works fine, desktop apps do not. OS: Windows 11 (latest version) Office version: Microsoft 365 (freshly reinstalled)

So, after working on this for a while - and NOT reinstalling Windows (that's insane) or Office (also insane) - I was able to get it to work again. This is what worked for me: Hit Windows key + R Type "services.msc" and press Enter Find "Microsoft Account Sign-in Assistant" in the list. Right-click and select "Restart." Find "Microsoft Cloud Identity Service" in the list. Right-click and select "Restart." Open Word, Excel, PPT, or whatever and try to sign in again. Worked immediately for me. Quick note to the Microsoft employees and advisors trying to "help" here: Please work to provide help, real assistance, rather than a simple-yet-insanely-un-fun solution like "Just reinstall the OS." That is not a solution.

After several uninstall/reinstall cycles for both the windows update and MS 365/Office and a session with Microsoft Support, the problem persisted. The solution for me was laughably simple: Run Excel as an administrator...Excel finally launched! Go to File > Account > Update Opption > Update Now All my Office apps now run normally.

I just want to chime and report that Jake Norton's assessment is correct. My experience: My machine had the service "Microsoft Cloud Identity Service" disabled. Not sure how that happened or why. After re-enabling this service, my Office products began behaving again.

Update: The March 21, 2026 update is supposed to fix the sign-in problem. March 21, 2026—KB5085516 (OS Builds 26200.8039 and 26100.8039) Out-of-band - Microsoft Support Windows 11, version 25H2 known issues and notifications | Microsoft Learn

Hey, I had the same issue and I just restarted my laptop. I gess I was lucky... But that's clearly the first thing to try ;) Good luck to others :)

Cannot sign in to Office apps - error 0x800704cf - Windows authentication broken

Danosch Zahedi 55

Issue: Unable to sign in to any Microsoft Office desktop applications (Word, OneNote) on Windows 11. Receiving error code 0x800704cf on every sign-in attempt.

What I've tried:

Reset network stack (netsh winsock reset, ip reset)
Cleared Windows Credentials Manager
Reinstalled Microsoft Office
Ran SFC scan — no integrity violations found
Deleted Office Identity registry key (HKCU\Software\Microsoft\Office\16.0\Common\Identity)
Ran Microsoft SaRA tool — no fix found
Test-NetConnection to login.microsoftonline.com port 443 — TcpTestSucceeded: True
Can sign in via browser at office.com without issues
Adding a new Windows user account also fails with "Something went wrong"

Conclusion: Network connectivity is confirmed working. Issue appears to be with Windows authentication system (WAM), not Office itself or network. Browser-based Office works fine, desktop apps do not.

OS: Windows 11 (latest version) Office version: Microsoft 365 (freshly reinstalled)

Jake Norton 130 Reputation points

2026-03-13T21:31:07.4766667+00:00

Is reinstalling Windows truly the only fix to this 100% Microsoft problem? Excel triggered the issue, and the only way to remedy it is to reinstall the OS? Sheesh.
Vincent B 5 Reputation points

2026-03-14T13:20:03.9466667+00:00

Same issue here, tried all options. NOT reinstalling the entire OS for an issue clearly caused by Microsoft.
Vincent B 5 Reputation points

2026-03-15T13:46:22.3366667+00:00

Reinstalling the OS did not work for me. Waiting for 12 hours did.
Markus 15 Reputation points

2026-03-15T21:46:17.4266667+00:00

Similar issue here. Coukd not login into my private Onedrive account with the no internet connection error. Business account worked fine. Only help was uninstalling the March Windows security update. After restart no problems with the login.
JoJoPhoto 0 Reputation points

2026-03-17T12:08:29.77+00:00

Same issue started for me today. Thankfully OneDrive is kinda working but 365 isn't, tried logging out and now can't get back in again.
lordofthedreams 5 Reputation points

2026-03-18T10:17:23.1833333+00:00

Uninstalling March Windows security update worked for me, too.
Eagle 10 Reputation points

2026-03-19T04:21:57.2266667+00:00

Same exact problem - Uninstalling the March security update fixed it for me too.
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Léo Blanqui 0 Reputation points

2026-03-19T21:29:48.51+00:00

Same issue here.
Steve S 10 Reputation points

2026-03-20T11:57:22.2+00:00
3rd time lucky (I hope). Since the 2026-03 Security Update (KB5079473) (26200.8037) I've had problems accessing Microsoft 365 and Outlook on Windows 11 PC. 1st workaround gained me access to Outlook and intermittent access to my Private Vault (so I moved files into my Vault temporarily for access). 2nd workaround - I removed the Security Update and then reinstalled it. I thought I'd got full access but 2 days later got error 0x800704cf back.

I'm not tech savvy so after a further search I came across:

Other Microsoft 365 Tool Repairs (Office/Apps)

For Office-based apps:

Right-click the Start button and select Installed apps (or Apps and Features).

Locate the Microsoft 365 product, select the ellipsis, and choose Modify.

Choose Online Repair to replace missing files.

This seems to have worked for me.
Angel DeLaCruz 0 Reputation points

2026-03-26T15:58:47.6166667+00:00

what actually work for me was uninstalling the recent microsoft windows security update
domenic pasquarelli 0 Reputation points

2026-03-28T20:27:10.3933333+00:00

Sometimes the solution is incredibly simple. I tried many of the things you did....I actually went as far as contacting Microsoft support which was pointless.

Run Excel as administrator.

Go to File > Account > Update Options > Update Now.

Can now run any Office App without issue!
b rus 5 Reputation points

2026-06-06T18:03:11.9466667+00:00

How can I uninstall the March Windows Security Update?

Answer recommended by moderator

Jake Norton 130

So, after working on this for a while - and NOT reinstalling Windows (that's insane) or Office (also insane) - I was able to get it to work again. This is what worked for me:

Hit Windows key + R
Type "services.msc" and press Enter
Find "Microsoft Account Sign-in Assistant" in the list. Right-click and select "Restart."
Find "Microsoft Cloud Identity Service" in the list. Right-click and select "Restart."
Open Word, Excel, PPT, or whatever and try to sign in again. Worked immediately for me.

Quick note to the Microsoft employees and advisors trying to "help" here: Please work to provide help, real assistance, rather than a simple-yet-insanely-un-fun solution like "Just reinstall the OS." That is not a solution.

Periperi 0 Reputation points

2026-03-15T04:57:20.67+00:00

Thank you so much! This worked for me.
Grendizer 65 Reputation points

2026-03-15T11:19:05.4666667+00:00

You hit the nail on this one! After many attempts and wrong advices, your solution worked!!
Vincent B 5 Reputation points

2026-03-15T13:45:49.5333333+00:00

I ended up reinstalling my entire OS. After that it still did not work! Waited about 12 hours and voila, worked again....
FIY My personal info was recently leaked in a giant hack, Odido Netherlands. I think this has something to do with it.
farmingsalt 5 Reputation points

2026-03-16T00:00:59.82+00:00

Couldn't connect to Microsoft Store or Game Bar and this worked perfectly.
Sebastian192 0 Reputation points

2026-03-16T12:13:40.1633333+00:00

Thank you. This worked wonderfully!
Alexia Barrios 0 Reputation points

2026-03-16T19:04:30.3566667+00:00

I was trying to do this, however my list didn't have "Microsoft Cloud Identity Service" as an option
Rasik Mistry 0 Reputation points

2026-03-16T20:04:59.41+00:00

Hi Jake, Thank you for posting your solution that resolved this issue for me.
JoJoPhoto 0 Reputation points

2026-03-17T12:12:24.71+00:00

Didn't have the Microsoft Cloud Identity Service option but worked by restarting the Microsoft Account Sign-in Assistant.

Thank you!
domenic pasquarelli 0 Reputation points

2026-03-17T14:00:03.9633333+00:00

I was so hopeful that this would work as i had tried everything else other than OS reinstall. I do not see the Microsoft Cloud Identity Service in the list of services.

Any suggestions?
J G 10 Reputation points

2026-03-17T20:06:15.3833333+00:00

Good job, this is the solution, thanks for actually taking the time to figure this out.
domenic pasquarelli 0 Reputation points

2026-03-17T20:33:32.6466667+00:00

Of course I restarted the Microsoft Account Sign-in Assistant, but Excel still does not start.
Grendizer 65 Reputation points

2026-03-18T08:52:38.2366667+00:00

Set both services so they start automatically.
AF 10 Reputation points

2026-03-18T10:16:41.93+00:00

Just registered to say thank you to you Jake Norton - your simple solutions worked for me after two days of battling with Windows.

For Microsoft's "advisors" - as Jake Norton said above, telling people blithely to simply reinstall the OS to fix an issue caused by Microsoft Windows is not a solution. If that's the best you can do, best to stay silent.
Michael G 5 Reputation points

2026-03-18T20:16:50.8233333+00:00

Great work and a big thanks. I was troubleshooting for hours till i found this thread. Mircoslop is getting more unstable by each day it seems.
Steve Byars 0 Reputation points

2026-03-21T18:54:51.6633333+00:00

Thank you!
Joan Janssen 0 Reputation points

2026-03-21T20:40:57.27+00:00

THANK YOU! THANK YOU! THANK YOU! This worked after hours of searching for help.
Jon Christiansen 0 Reputation points

2026-03-24T19:15:34.45+00:00

This did trick for me! In my case there was no "Microsoft Cloud Identity Service" but restarting "Microsoft Account Sign-in Assistant" fixed the issue. Thanks so much for taking the time to post, saved me a ton of time.
Preston Cottrell 0 Reputation points

2026-04-04T21:20:07.6633333+00:00

Thanks!
GT W 0 Reputation points

2026-06-15T04:48:56.3866667+00:00

It works! Thank you!

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domenic pasquarelli 0 Reputation points

2026-03-28T20:38:23.01+00:00
After several uninstall/reinstall cycles for both the windows update and MS 365/Office and a session with Microsoft Support, the problem persisted.

The solution for me was laughably simple:
1. Run Excel as an administrator...Excel finally launched!
2. Go to File > Account > Update Opption > Update Now
All my Office apps now run normally.
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HG 0 Reputation points

2026-03-26T23:41:56.79+00:00

I just want to chime and report that Jake Norton's assessment is correct.

My experience: My machine had the service "Microsoft Cloud Identity Service" disabled. Not sure how that happened or why. After re-enabling this service, my Office products began behaving again.
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Ramesh 181.9K Reputation points Volunteer Moderator

2026-03-22T07:26:52.2466667+00:00

Update:

The March 21, 2026 update is supposed to fix the sign-in problem.

March 21, 2026—KB5085516 (OS Builds 26200.8039 and 26100.8039) Out-of-band - Microsoft Support

Windows 11, version 25H2 known issues and notifications | Microsoft Learn
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Quentin Desjobert 0 Reputation points

2026-03-22T07:22:28.5666667+00:00

Hey,

I had the same issue and I just restarted my laptop. I gess I was lucky... But that's clearly the first thing to try ;)

Good luck to others :)
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Cannot sign in to Office apps - error 0x800704cf - Windows authentication broken

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