To disable password caching:

REGEDIT4
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Network]
"HideSharePwds"=dword:00000001
"DisablePwdCaching"=dword:00000001

To require users to provide a valid network password at login, and prevent them from logging in by pressing the Escape key:
REGEDIT4
[HKEY_LOCAL_MACHINE\Network\Logon]
"MustBeValidated"=dword:00000001

To incorporate a Windows NT domain login into the workstation login prompt, and to change the initial workstation login from one using a local Windows password to one using password validation against a Windows NT domain:
REGEDIT4
[HKEY_LOCAL_MACHINE\Network\Logon]
"LMLogon"=dword:00000001

To alter the screen saver so that it authenticates users against
the Microsoft network provider, rather than locally,
run this .reg file:

REGEDIT4
[HKEY_LOCAL_MACHINE\System\CurrentControlSet\control\PwdProvider\SCRSAVE]
"ProviderPath"="msnp32.dll"
"UseMasterKey"=hex:01,00,00,00
