Starting with Windows 2000, you can log on to the network domain where the domain controller is not reachable...
usually this feature is useful for portable computers so that when people who use them are out of office, can still use the network account and the associated policy.
To disable this feature, run the application regedit.exe and select the following key:
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon]
edit or create (if doesn't exist) the following value:
"DeleteRoamingCache"=dword:1
