Like in previous Windows versions, the built-in administrator account is disabled by default in Windows 8. You can easily enable it in Windows 8 with the command net user administrator /active:yes from a command prompt with admin privileges. However, if you are locked out of your computer, for example because you forgot your password, you need to enable the administrator account offline—that is, from a second Windows instance—to be able to log on with administrator rights.
A few days ago, I described how you reset a forgotten Windows 8 password for a local user account. Ian mentioned in a comment that this procedure doesn’t work for Microsoft accounts (connected account). Unfortunately, this is true. The workaround described here uses the built-in Windows 8 administrator account to access the data of the Microsoft account for which you forgot the password.
If you forgot the administrator password, it is no big deal to reset the password on a Windows 8 computer. This easy-to-follow, step-by-step guide shows how. The procedure described here also works for Windows 7, Windows Vista, and Windows XP, although I will use a Windows 8 boot DVD in the guide.
With Windows 8 and its increased support for tablet/touch-based devices, we now have the option to use a new authentication mechanism: Windows 8 picture password.