Can't upgrade from MVC2 to MVC3

Question

I've got myself an MVC2 web applicatin using .NET Framework 4 and am following these instructions to the T. However at step 10 when I save the updated ProjectTypeGuids I get a message saying "The project file projectname.csproj cannot be opened. The project type is not supported by this installation."

I do have MVC3 installed and am running VS2010, so I don't know what could the going wrong. Anyone have any thoughts on the matter? Thanks!

EDIT:

For what it's worth. If I create a blank project from scratch, I have the ability to create a new MVC3 project. However, if I right click on my solution and click add->New Project... I can only add MVC2 projects. This leads me to think that the solution is configured somehow to only support MVC2, however I can't figure out how to change it.

Answer 1

There is an extra package which is ASP.NET MVC 3 Tools Update, you must download and install it too.

Solution 1:

Open the visual Studio Find In Files Dialog and Select your project folder, then search for old GUID and replace it with new one exactly. Backup the directory before doing this. Actually You must select the whole solution folder and search all the files not a specific extension.

Solution 2: You must take a careful look at your csproj and sln files and compare it with a working one on your system to find the difference. if you have file compare tools like winmerge, use it to compare files character by character