Was trying to install Silverlight tools at work, but my development machine has no internet connection and silverlight_tools.exe just wont install. It seems like it was trying to download something which I later found out was the silverlight developer runtime.
Even if you already installed the developer runtime separately the installation will still attempt to download the latest version of it. Found this page from Tim Heur which documents how to install silverlight offline.
I personally think that Microsoft’s approach to distributing the Silverlight tools is wrong. It just makes it difficult for people to work. They should just bundle one copy of the developer runtime in and save a lot of people some time trying to google for the answer.