 <p>As a reference for future users:</p> <p>Don't forget to also <strong><em>INSTALL</em></strong> the framework you target! (I, myself, thought that because all the folders (v4.0x, v2.0X, etc.) were there I had all frameworks. NOT! It turns out I only had the .NET 4.0 <strong>client profile</strong> installed on my system and could not find the System.Web, even though the right framework was targeted.</p> <p>Anyway, download your needed .net framework here: <a href="http://www.microsoft.com/download/en/search.aspx?q=.NET%20framework" rel="nofollow">.NET Frameworks Microsoft Downloads</a></p>