Managing personal Outlook.com account settings, security, and privacy
This is because your email has been fused to windows. Your device is now listed as a "trusted device". This is applied to any new device that is purchased and requires an email to activate. To stop this from happening and activate a manual login, you must go to your Microsoft settings at https://www.microsoft.com. Sign in and proceed to finding the settings for Security. The new website layout will then ask you to click on the "more security settings" option. My account asks for a confirmation identity code that sends it to another e-mail or in a text message to my phone. After the additional settings pop up, scroll to the very bottom and you should see "Trusted Devices" 2nd from the bottom. Clear the trusted devices and your problem has now been fixed.
It is because any new device is automatically listed as a trusted device and trusted devices avoid the safety protocols of having to sign in with an email and password every time to access your inbox. This will prevent any device you have used that is labeled as "trusted", so if there was a device you wanted to avoid a login, you will now have to log back in to that device and click the "keep me signed in" checkbox or reactivate it as a trusted device from the devices own settings.