The VS (Microsoft Visual Studio2010) tool opens the application that is required for the project, and the workaround for the application that appears without the installation (. csproj)

1. To open this file, select Open from the list to see if the Open project file opens in a way that is not Visual Studio, if Micrisoft Visual Studio version Selector. The solution is to use visual Studio opens and chooses to always open the project file with it, which is not the next time. What else will happen that causes the Open association of the project file to be tampered with? This can occur because the SQL Server database is installed, and after you install the SQL Server 2005 database.
2. Workaround: Right-click on the csproj end of the file, select "Properties", "open mode", positioning it to vs2010 exe, click "OK" on it.
3. If the above method still does not work, you can use the following method, that is, to do this, first open the VS 2010 tool, select "Tools" in the toolbar, select "Options", select "Source Control", as shown in, select "None" or the second Visual Studio Team Foundation server is also available.
4. After you open the. sln or. csproj

The VS (Microsoft Visual Studio2010) tool opens the application that is required for the project, and the workaround for the application that appears without the installation (. csproj)