Since Windows 8, users have been able to sign into Windows using their Microsoft account. Windows 10 kind of forces you to use your Microsoft account. As you can see below my Windows 10 Laptop is being sync’d with my Hotmail account:

However, those of you who are security conscious may want to turn this off and if you haven’t done so already how to you prevent users from continuing to use their Microsoft account? It’s quite simple with Group Policy. Open the Group Policy Management console on a Domain Controller and navigate to Computer Configuration > Windows Settings > Security Settings > Local Polices > Security Options:

In the policy Accounts: Block Microsoft accounts define the policy however you see fit for your organisation:

Just be aware that if Users have already added it and you select Users can’t add Microsoft accounts they will still be able to login and sync!!

The Users section of Settings app will now show “Some settings are managed by your organization” message.