I was having trouble with updates on server. It was complaining about the proxy settings. So, I wanted to have the Windows Update use a different proxy configuration. The following commands can be used to manage the proxy settings from the command line:

Display the current settings:

netsh winhttp show proxy

Set the proxy:

netsh winhttp set proxy proxyservername:portnumber

Set proxy and bypass options:

netsh winhttp set proxy proxy-server=”proxyservername:portnumber” bypass-list=”*.mylocal.domain”

And then, when you really screw something up and just want to start over. Reset:

netsh winhttp reset proxy