How to declare a network proxy for all windows programs to use?
Could you be a bit more descriptive, you'll get better answers
Open IE go to internet options, go to connections, lan settings ->proxy settings
:P Not really an answer, just my tech support days shining through.
A quick search on Bing brought this post.
The guy there was able to do what you want using WMI.
.NET framework WebRequest use Internet Options for current user context (accessible from control panel). As if it is set for IE, it will be used by .NET WebRequest.
But when WebRequest will run under account such as "NT AUTHORITY\NETWORK SERVICE", for example from ASP.NET application, there's no Internet Options set for this user. That way you have to play with registry.
For more, read article "Take the Burden Off Users with Automatic Configuration in .NET"