JSI Tip 9236. How can I prevent a user from accessing the Internet?

You can prevent a user from accessing the Internet by forcing Internet Explorer to use a proxy server that is set to an invalid address.

NOTE: Any program that uses the ProxyEnable and ProxyServer settings at
HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionInternet Settings will be prevented.

You should also set Connection Settings and Connwiz Admin Lock, both REG_DWORD data types, at
HKEY_CURRENT_USERSoftwarePoliciesMicrosoftInternet ExplorerControl Panel, to 1 to prevent the user from changing these settings.

These setting must be set before the user logs on, but can be set in a logon script.

You can use REG.EXE, built into Windows XP, Windows Server 2003, and later, or installed on Windows 2000 from the Support Tools on the operating system CD-ROM:

reg add "HKCUSoftwareMicrosoftWindowsCurrentVersionInternet Settings" /V ProxyEnable /T REG_DWORD /F /D 1reg add "HKCUSoftwareMicrosoftWindowsCurrentVersionInternet Settings" /V ProxyServer /T REG_SZ /F /D "10.1.0.1:2222"reg add "HKCUSoftwarePoliciesMicrosoftInternet ExplorerControl Panel" /V "Connection Settings" /T REG_DWORD /F /D 1reg add "HKCUSoftwarePoliciesMicrosoftInternet ExplorerControl Panel" /V "Connwiz Admin Lock" /T REG_DWORD /F /D 1

or you can use regedit /s filename.reg, where filename.reg contains:

REGEDIT4[HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionInternet Settings]"ProxyEnable"=dword:00000001"ProxyServer"="10.1.0.1:2222"[HKEY_CURRENT_USERSoftwarePoliciesMicrosoftInternet ExplorerControl Panel]"Connection Settings"=dword:00000001"Connwiz Admin Lock"=dword:00000001