IIS/WWWRoot in Web Matrix
WWWRoot is a hidden folder (by default) and can't be displayed in directory listing in Web Matrix due to security reason. There's a File Explorer/Directory Listing like workspace in Web Matrix, where all of the files in you hard diskes will be displayed over there for you to drag and drop on to designer pane or perform other actions, however, you can't see the folder of WWWRoot come with the IIS by default...
If you ever see this happen, the first question is.. Do you have IIS installed in your local machine? This question look like stupid but it's obvious. Web Matrix come with a Cassini Web server so that you don't actually need to install IIS in order to "play" a web page, and you can select/create any folder to host your web page out of the default WWWRoot folder (and you can of course put your file under WWWRoot and use your IIS directly in Web Matrix :)
The second question to you is: check out these thread. You can see the reason and solution over there and the point is run a command line statement as to unhide the hidden/system folder/file. I'm not sure do VS.NET 2005 have such "security" consideration as in Web Matrix, but at least I know MS did a lot of security consideration (this "protection" is a good stuff anyway).