How do I configure proxy settings for LOCAL SYSTEM?

If I edit Proxy Settings through the Control Panel, the settings are stored in HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ProxyEnable and ...\ProxyServer. These settings are of course not used when running as a service under LOCAL SYSTEM.

So I tried setting ProxyEnable and ProxyServer under HKEY_USERS\S-1-5-18\... (as well as HKEY_USERS\.DEFAULT\... and all the other users on the system), but that does not work.

How do I set the proxy settings for the LOCAL SYSTEM user?

It is actually the value in Software\Microsoft\Windows\CurrentVersion\Internet Settings\Connections\DefaultConnectionSettings that is used.

Since that is not easily modified, you can modify the proxy settings for a user, export the registry key, modify the path in the exported file to HKEY_USERS\S-1-5-18 and reimport it.

First, run cmd as administrator to open a command prompt.

Command to copy proxy settings of current user to WinHttp:

netsh winhttp import proxy source =ie

To reset the proxy to default settings:

netsh winhttp reset proxy

To show proxy settings of current user:

netsh winhttp show proxy

Another way, albeit much messier, is to use psexec to open a command prompt running as LOCAL SYSTEM, then from that open iexplore.exe, modify the settings appropriately.