Do you want to configure Windows Update to use a proxy server? This excerpt from Tulloch, Northrup, et al.'s Windows 7 Resource Kit will help you configure your proxy with Netsh.
Windows Update can use an HTTP proxy server. However, configuring Windows Internet Explorer is not sufficient to configure Windows Update because Windows Update uses Windows HTTP Services (WinHTTP) to scan for updates and BITS to download updates.
You can configure Windows Update to use a proxy server in two ways:
Web Proxy Auto Detect (WPAD) settings are configured. The WPAD feature lets services locate an available proxy server by querying a Dynamic Host Configuration Protocol (DHCP) option or by locating a particular Domain Name System (DNS) record.
Use the Netsh command-line tool, which replaces the Proxycfg.exe tool.
To use the Netsh command-line tool, first switch to the Netsh Winhttp context. Then, use the show proxy command to view settings or the set proxy command to define your proxy server configuration settings. For example, you can run the following command to view current proxy server settings.
Netsh winhttp show proxy
The following commands demonstrate how to configure proxy server settings.
Netsh winhttp set proxy myproxy Netsh winhttp set proxy myproxy:80 "
;bar" Netsh winhttp set proxy proxy-server="http=myproxy;https=sproxy:88" bypass-list="*. contoso.com"
Alternatively, if you have configured Internet Explorer proxy server settings correctly, you can import settings from Internet Explorer into WinHTTP by using the following command.
Netsh winhttp import proxy source=ie
Netsh winhttp reset proxy