Usually Windows 2000 and Xp, show the last user is logged in to the machine. If you want to hide it you have to add a new value on registry, is simple…

1. Open the registry:
2. Start -> run -> regedit
3. Now explod the tree to:HKEY_LOCAL_MACHINE\SOFTWARE\ Microsoft\Windows\CurrentVersion\policies\system
4. To the right panel, click with right button of mouse into blank area
5. choose NEW-> DWORD value
6. input “DontDisplayLastUserName” (be careful, is case sensitive!)
7. double click on new entry, a the mask put “1″ to value

If you want to disallow this feature, simply change the value from 1 to zero.