In Windows 10, Microsoft Account is the default way of signing in. This means that the OS requires your Outlook.com, Hotmail, MSN, or Live ID email address and password to sign-in to Windows. It is still possible to sign in using a local account that does not involve internet-based credentials, but the option to do so is hidden behind various buttons.
There are many online services that allow you to reset your forgotten account password by answering security questions that you had answered while creating your account. The same feature has been added to Windows 10. You can add Security questions to local user accounts in Windows 10.