Sometimes you want to perform several administrative tasks and don’t want to be bothered by UAC (User Account Control) every time. This is especially true when installing programs after a clean install of Vista, for example. To log on as Administrator, you need to open an elevated command prompt. The easiest way to do this is to type cmd in the Start menu Search box, then press Ctrl+Shift+Enter, respond ‘yes’ to the UAC prompt and then type the following command:
net user administrator /active:yes
From now on, the Administrator will appear on the Welcome screen. Be sure to set a strong password when logging in initially!