How to login as Administrator in Windows XP?

• 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.