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

Question

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 125 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.
Deleted

This comment has been deleted due to a violation of our Code of Conduct. The comment was manually reported or identified through automated detection before action was taken. Please refer to our Code of Conduct for more information.
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!

Answer recommended by moderator

8 additional answers

Your answer

Jake Norton 125 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.
Deleted

This comment has been deleted due to a violation of our Code of Conduct. The comment was manually reported or identified through automated detection before action was taken. Please refer to our Code of Conduct for more information.
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!

Answer 1

Jake Norton 125

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!

Answer 2

Aaron Ibbotson 45

I had a similar experience, trying many of your same solutions. In my case, I suspected that Microsoft Store was part of the issue.

I therefore uninstalled the March Windows Security update, determined everything was working again, then logged into my Microsoft Store (since I was not logged in). I then re-ran the Windows Security update. Once it was loaded and my computer restarted, all my Microsoft apps worked okay.

Hope this helps.

召斌王 0 Reputation points

2026-03-17T00:58:08.75+00:00

uninstalled the March Windows Security update
Eagle 10 Reputation points

2026-03-19T04:22:57.4+00:00

Thanks for this, uninstalling the March update was the ticket!
Aaron Abraham 10 Reputation points

2026-03-19T08:00:40.2733333+00:00

Thanks for this. In my case, I uninstalled the update, and then let WIndows reinstall it back straight away. Restarted the machine, and now Office apps seem to be ok
Angel DeLaCruz 0 Reputation points

2026-03-26T15:59:11.4733333+00:00

this worked for me thanks
JH L 0 Reputation points

2026-03-31T15:06:23.6466667+00:00

Thanks, goodness. It works. I don't understand why MS is getting worse and worse.

Answer 3

Ahmed Ali 0

tried to change the network from Wifi to cable and that solve the issue

0 comments

Answer 4

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Answer 5

Sumit D - IA 167.2K Independent Advisor

Hi Danosch,

You have done a lot of good troubleshooting. I think it's time to reinstall Windows, keeping everything.

Please try a repair install as the next step. It keeps everything, including apps and files, and reinstalls Windows.

Repair Install Windows 11 using an ISO file

https://www.yourwindowsguide.com/2021/08/repair-install-windows-11-using-an-iso-file.html

Download Windows 11 ISO file from the following link:

https://www.microsoft.com/software-download/Windows11

Under Download ISO file, select Windows 11.
Click Download and choose the Language in which Windows is installed.
Click 64-bit Download to start the download.
When downloaded, open the ISO file, and run Setup.exe to start the upgrade.

I hope this information helps. If you have any more questions, don't hesitate to reach out.

Otherwise, please take a moment to rate the answer. Wishing you good luck!

J G 10 Reputation points

2026-03-17T20:07:39.2833333+00:00

This is the most unhelpful solution I have ever seen here. Please be better. Delete this so no-one accidentally follows your advice please.
AF 10 Reputation points

2026-03-18T21:34:28.4133333+00:00

Sorry, but telling users to reinstall Windows when the problem was caused by Windows and has an easy fix, is not good customer service. Users expect more from Microsoft customer support than "just reinstall Windows".
AF 10 Reputation points

2026-03-22T18:42:35.8266667+00:00

As of 22nd March 2026, the latest Windows update (KB5085516) (26200.8039) is listed as specifically fixing this issue which Microsoft created in the previous Windows update. I have downloaded this and it does seem to permanently fix the issue (so far).

To Sumit D - IA - please delete your post, lest others read it and mistakenly think it is helpful in any way, shape or form. It is not. I note you are listed as an "Independent Advisor" and are not a Microsoft employee. Perhaps in future you might wish to think before posting 'solutions' akin to using a sledgehammer to crack a nut.

To all the other Microsoft Windows ~~victims~~ users who did painstaking investigations and provided workarounds, THANK YOU.
Grendizer 65 Reputation points

2026-03-23T11:52:50.9033333+00:00

true AF!

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

8 additional answers

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