cannot connect to icloud from windows 11 PC

I was racking my brain on this one for a while until I noticed the Windows 11 machine that was working was older WIFI Card. Newer Windows 11 machine has the Killer(R) Wi-Fi 6E AX1675i 160MHz Wireless Network Adapter.

I searched the web and found this thread.

When I loaded the "Killer Intelligence Center" I noticed warning messages indicating that my router is not compatible with newer capabilities on this Killer WiFi Card.

Work around:

1. Right click start and load Computer Management
2. Find Killer Services under the Services and Applications
3. Set both Killer Network Service and Killer Analytics Service to Disabled
4. Find both these services in task manager and stop the both
5. Log into icloud.com without issue; Joy!

Thanks rivrbend!

Hey rivrbend,

There are several things you can check for this issue. Please check the following steps below:

How to tell if your security software might be causing an issue

Security software created by companies other than Apple can prevent iCloud for Windows or iTunes from connecting to Apple servers or to devices. Sometimes, you might see a numeric error message when you sync, update, back up, or restore your device.

If your security software is causing an issue with iCloud for Windows

* You can't sign in with your Apple ID.

* You see "Verification Failed: An unknown error occurred" or "An error occurred during authentication. Please try again." 

* You see "Your setup couldn't start because your username or password is incorrect" or "Your setup couldn't be started because the iCloud server stopped responding."

* iCloud services won't update. 

For additional steps, please check out this article as well: Resolve issues between iCloud for Windows or iTunes and third-party security software

Let us know how it goes.

Cheers!

thanks to riverbend for pointing me in the direction of killer network service. people seam to be disabling it completely but i found my computer had a app installed called "killer intelligence centre" and it seams to be the control software for the wifi adapter. you dont have to permanently disable it i have gone into settings and turned all options off on this page below

on one of the screens it shows the priority its gives to each app and icloud is the least priority which could be why it was intermittent and kind of worked sometimes. maybe i will try to switch each one on and see which feature is stopping icloud. its not the whole software by the looks of it.

I am also having problems when I try to connect to Icloud on my PC through Edge and Chrome. I get the following message:

Connection Error.

iCloud encountered an error while trying to connect to the server.

I have updated everything, I have cleared the cache. I have cleared all of the temp files. I have turned off the virus and other protection. I have had the PC reviewed independently. I have gone through Apple Support. No improvement.

It worked last week. Today I cannot get through. However, once or twice I got through long enough to confirm the third-party authentication, then it kicked back into the error message.

Any suggestions would be appreciated.

Performing a "clean boot", disabling all non-Microsoft Services, is what finally allowed me to login to iCloud. I followed the instructions in this thread:

https://answers.microsoft.com/en-us/windows/forum/all/attempting-to-start-icloud-for-windows-on-windows/f5b1cba6-7677-494f-a06b-a9166bcb8c71

I have not yet started adding services back to see which one is actually causing the conflict.

Anyone find the source of the problem yet (a driver or program)?. I spent 4 hours with Apple Support going through many of the trouble shooting steps, including removing antirus software, reinstalling icloud and itunes and creating a new windows user admin account, but no success yet in fixing the issue or identifying a specific cause. I have yet to disable and enable services and was hoping someone here had done that. My issue started a little over a week ago when I found my icloud calendars would not sync with my Dell Windows 11 PC. Feels like there must have been a Windows update or simialr that drove this. My problem is with the app and the icloud website. Occassionally I have got through to the website, but I always get a server error with the app. I have no issues with my windows 10 laptop, iphone or ipad (all on the same wifi network).

Thank you so much "riverbend". I disabled the service, rebooted and now icloud is fully functional. I have reported this (temporary) solution to the Apple Support team for my ticket. I am not sure of a path to dicuss with Intel. Fortunately, I run my PC on an ethernet connection and not wirelessly so assume there will be no impact keeping this disabled for now. I assume there ar emany Killer wifi cards on the street so this could be causing many people problems. Hopefully they come here and follow your guidance until Intel (or Apple) provides a permanent fix.

It's not Microsoft. The Killer Network suite is owned by Intel, and in my case it shipped with new Dell hardware. The problem is that all of these corporations are too big and too "perfect" to listen to the little guys like us or anyone else, including each other. For me, the bigger question is - what are Apple doing about it? It is they who should be resolving this with Intel. iCloud is not an insignificant part of their product portfolio.

I solved this problem by going through a VPN. That, after many days of troubleshooting and a few calls with Apple. Tried many things. IMO, it's a problem with my ISP because I bypassed everything else without improvement. Only when connecting through a VPN or a cellular hotspot, the problem went away.

You don't need to delete anything, just disable "Killer Network Service" in task manager services.

I have the same issue and I have done exactly what you have with no joy. Very frustrating !!

I disabled Killer Network Service on both of my laptops, and it solved the problem.

Thank you very much! =)