Error: "The project type is not supported by this installation."

There could be many cases that cause this error. One such case is when you try to open/migrate web project application developed in Visual Studio 2003 in the Visual Studio 2005. The reason being VS 2005 does not come with web project template because VS 2005 comes with new web application development & compilation machanism that is called website model. for more details click here.

So to solve this problem you will have to install following updates on your machine.

1. Microsoft Visual Studio 2005 - Update to Support Web Application Projects
2. install Microsoft® Visual Studio® 2005 Team Suite Service Pack 1

Note - To fully enable Web Application Projects in Visual Studio 2005, you will have to install both these updates.

Reference- http://msdn.microsoft.com/en-us/library/aa730880(VS.80).aspx