Connection Error to iCloud server

Hello SOS_please,

Often times when you are unable to open iCloud for Windows or iTunes, your security software might be the cause of this issue. Therefore, we'd like to provide you with a few steps that may be able to assist you:

"Things to check first

Before you change your security software's setup: 

• Make sure that the date, time, and time zone are set correctly on your computer. Learn how to update these settings on a Mac or on a PC. 
• Log in to an administrative user account, not a guest account. Learn how to do this on a PC. 
• Update to the latest version of iCloud for Windows or update to the latest version of iTunes.
• Make sure that you have the latest software on your Mac or on your PC.
• Make sure that you set up Windows Hello. Learn how to set it up. 
• Make sure that you only have one type of security software installed. If you have more than one type of security software installed, you might experience performance issues.

Test your connectivity

1. Check your hosts file to make sure that it's not blocking iTunes from communicating with Apple's servers.
2. If you’re having issues using AirPlay, Home Sharing, iTunes, or Remote, test the connectivity between the computers or devices in your house. They should be connected to the same network and subnet in order to function properly.

Test your security software

If you still have trouble after you test your connectivity, your security software could be interfering with your computer's connection with iCloud for Windows or iTunes.

In some cases, it might be necessary to temporarily remove your security software to isolate an issue. Some Internet security apps don’t uninstall completely, so you might need to download and run a cleanup utility for your security software for it to be completely removed.

Work with your security software provider to allow the complete list of ports and services that Apple products use or if you need help with uninstalling their software."

More details here: Resolve issues between iCloud for Windows or iTunes and third-party security software

Let us know if this helps.

Take care.

I found the following solution works for Windows machines with a Killer Network Wifi Adapter. Type msconfig to bring up the system configuration. Then in the services tab, disable Killer Network Service. Reboot your PC and icloud server and icloud app work. I had no issue with wifi as I run on ethernet. I don't know the impact (if any) of disabling this service on a wifi network. I spent many hours with Apple beforehand but to no avail. The solution was originally posted here on the apple forum. cannot connect to icloud from windows 11 … - Apple Community

Lots of users are reporting this issue. An update of some kind in August has caused a problem - either a Windows update or the iCloud app.

Thanks. That's interesting as that worked for me too. I have the Killer network service and there was an update vis intel for this during August. Perhaps this problem is linked to that?