System-Wide Proxy Settings in Windows Regedit

Configuring a system-wide proxy via the Windows Registry (Regedit) allows administrators to route all network traffic on a machine through a designated proxy server, applying settings across all user accounts and system services. This article covers the exact registry paths and key values required to configure, enable, and enforce machine-wide proxy settings in Windows.

1. The Primary Registry Keys for Proxy Configuration

Windows handles proxy configurations at both the per-user and per-machine levels. For system-wide proxy settings, the relevant keys are located in HKEY_LOCAL_MACHINE.

• Machine-Wide Internet Settings:
  HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Internet Settings
• Group Policy Managed Settings:
  HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings
• WinHTTP (Services and System Traffic):
  HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Connections

2. Enforcing Machine-Wide Proxy Over Per-User Settings

By default, Windows applies proxy settings on a per-user basis (HKEY_CURRENT_USER). To force the entire operating system to use the settings defined in HKEY_LOCAL_MACHINE, you must modify the ProxySettingsPerUser policy:

1. Navigate to:
   HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings
2. Create or modify a DWORD (32-bit) Value named ProxySettingsPerUser.
3. Set the value to 0.

Setting this value to 0 makes proxy settings apply to all users on the computer instead of individual user profiles.

3. Key Values for Configuring the Proxy

Within HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Internet Settings (or the equivalent Policies path), the following values define the proxy behavior:

• ProxyEnable (DWORD):
  • 1 = Proxy enabled
    
  • 0 = Proxy disabled
• ProxyServer (String / REG_SZ):
  • Sets the IP address and port (e.g., 192.168.1.100:8080 or proxy.example.com:8080).
• ProxyOverride (String / REG_SZ):
  • Specifies addresses that bypass the proxy, separated by semicolons (e.g., localhost;127.0.0.1;<local>).
• AutoConfigURL (String / REG_SZ):
  • Specifies the URL for a PAC (Proxy Auto-Configuration) script if using automatic configuration.

4. Configuring WinHTTP Proxy for System Services

Background system services, such as Windows Update, use the WinHTTP stack rather than the standard Internet Explorer/WinINet stack.

• Registry Location:
  HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Connections
• Value Name: WinHttpSettings (Binary / REG_BINARY)

Because WinHttpSettings is stored in binary format, it is standard practice to set it via the Command Prompt using the following command, which writes directly to the registry:

netsh winhttp set proxy 192.168.1.100:8080 "<local>;*.example.com"

To import the proxy already configured in the registry via WinINet to WinHTTP, run:

netsh winhttp import proxy source=ie