Note: This functionality requires Windows NT Service Pack 4 or higher.
Key:[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System]
Value Name: DisableLockWorkstation
Data Type: REG_DWORD
Data:(0 = disabled, 1 = enabled)
More info: http://support.microsoft.com/support/kb/articles/q174/8/40.asp




