A user's proxy setting are normally configured with Group Policy at User Configuration / Windows Settings / Internet Explorer Maintenance / Connections / Proxy Settings (Preference Mode).

You can override these settings for a specific computer by setting Make Proxy Settings Per Machine (rather than per-user) at Computer Configuration / Admin Templates / Windows Components / Internet Explorer to Enabled, which sets the ProxySettingsPerUser Value Name, a REG_DWORD data type, to 0. Unfortunately, Group Policy does not allow you to set the required ProxyEnable, ProxyOverride, and ProxyServer Value Names.

You can use PolicyMaker™ Registry Extension freeware or, if you only have a few computers to configure, you can edit the registry using REG.EXE, built into Windows XP, Windows Server 2003, and later operating systems, or installed from the Windows 2000 Support Tools. As an example::

<font size="1">REG ADD "\\ComputerName\HKLM\SOFTWARE\Policies\Microsoft\Windows\CurrentVersion\Internet Settings" /V ProxySettingsPerUser /T REG_DWORD /F /D 0
REG ADD "\\ComputerName\HKLM\SOFTWARE\Policies\Microsoft\Windows\CurrentVersion\Internet Settings" /V ProxyEnable /T REG_DWORD /F /D 1
REG ADD "\\ComputerName\HKLM\SOFTWARE\Policies\Microsoft\Windows\CurrentVersion\Internet Settings" /V ProxyOverride /T REG_DWORD /F /D 1
REG ADD "\\ComputerName\HKLM\SOFTWARE\Policies\Microsoft\Windows\CurrentVersion\Internet Settings" /V ProxyServer /T REG_SZ /F /D "192.168.0.1:80"</font>
Where:
<b>ProxySettingsPerUser</b>  of <b>0</b> is per computer and <b>1</b> is per user.

<b>ProxyEnable</b>           of <b>1</b> is enabled and <b>0</b> is disabled.

<b>ProxyOverride</b>         of <b>1</b> bypasses the proxy for local address and <b>0</b> does not.


<b>ProxyServer</b>           is the IP address and port, use xxx.xxx.xxx.xxx:nn syntax.
NOTE: When using Group Policy and/or PolicyMaker™ Registry Extension freeware, be sure to filter the policy so that it applies to only the computers you wish to configure.