VS2008 cannot open csproj file?

When I double click the csproj file on the compturer in the lab. It says "...Make sure the application for the project type (.csproj) is installed."  That's very strange, because the Vs2008 is installed with C# component. I didn't know why, then I went to "about visual studio" and saw that the c# component is not installed. All the things are about SQL Server. Then I realized that this visual studio is with SQL server 2005. Because SQL Server 2005 requires VS2005. And this VS2005 is associate with csproj file, but it has no c# component, it will encounter problem opening csproj file. The solution is starting VS2008 before double clicking on the csproj file. Then the opearating system will open this file using vs2008 instead of the fake vs2005.