- Click Start, Run and type Regedit.exe
- Navigate to the following key:
HKEY_LOCAL_MACHINE \ SOFTWARE \ Microsoft \ Windows NT \ CurrentVersion \ Winlogon \ SpecialAccounts \ UserList
- Use the File, Export option to backup the key
- Create a new DWORD Value named Administrator
- Double-click Administrator, and set 1 as its data
- Exit the Registry Editor.