Add Administrator Account to Log In Screen
When Windows XP is first installed it requires you to enter at least one name of a user who will access the computer. Once you create this name the default Administrator account vanishes. To access it, press Ctrl-Alt-Delete twice at the Welcome screen to retrieve the standard Windows 2000 logon dialog. Log on as Administrator from this point. To log the Administrator off, click [Start] [Log Off] and [Log Off] when the [Log Off Windows] selection box appears. The Log On screen with the available users will be displayed.
To Make the Administrator Account Always Visible on the Login Screen
1 [Start] [Run] [Regedit]

2 Registry Key: HKEY_LOCALMACHINE\SOFTWARE\Microsoft\Windows
3 NT\CurrentVersion\Winlogon\SpecialAccounts\UserList

4 Modify/Create the Value Data Type(s) and Value Name(s) as detailed below.
5 Data Type: DWORD// Value Name: Administrator
6 Setting for Value Data: [0 = Disabled / 1 = Enabled]
7 Exit Registry and Reboot

- srikanth dhanwada