Windows NT / Windows 2000 and Windows XP has a security setting to hide the last
logged onto account. The hack to block the last logged onto account is found in
Registry Tip #70. Windows XP adds the
ability to hide accounts from the Logon dialog:
UserList normally contains special accounts like the IUSR and IWAM accounts but
you can add normal accounts to have them hidden from the Logon dialog list. For
example, to hide my account Wayne Maples , I would add a
subkey to UserList of type REG_DWORD named Wayne Maples with a value of 0.