Windows 8.1 Security Code

Security Code

In both of these Microsoft Account sign-in paths you will also see an option to send a security code to a phone or email account you have configured in your Microsoft Account security settings. You must receive the code on another device and then enter it in the next step. This will make the PC a trusted device for your Microsoft Account.

Note: There is an option to skip this step, as shown above. If you skip the step then features only supported on a trusted device will be disabled.This includes the new Windows 8.1 settings restore feature, and password sync feature introduced in Windows 8.