MacBook Air stuck on 'some iCloud data isn't syncing' during Apple Account update

Ok everyone. I just fix this issue. Let me explain to you.

If you used to own a windows machine and just purchased a MacBook you need to read this. After completing windows migration assistant, I am unable to install anything on my new Mac. I cannot login to my account online and error message "Some icloud data isn't syncing" keeps appearing. This has also caused me unable to do iPhone mirroring. So the problem is MacBook has copied your windows login and this is causing all the above failures. So what you should do? Here are the steps.

1. On your MacBook go to settings go to Users and Group. Here you can see your windows profile picture and username.
2. Add a new user. You cannot use the same username as your windows. Just do any name. You can change it later on. Enter your Apple ID email or phone number that is similar to your iPhone. Choose as an admin.
3. Now you will have two admin accounts. In order to remove the windows account you need to login as the new user.
4. Log out and login as the new user. Here you can create an apple account (if you don't have any) or login to your apple account. Make sure the id you use from your iPhone and Mac are similar.
5. Go back to the settings -> Users and Group and remove the other account.

Everything else will work like wonder. Phew! Took me four days to figure this out.