This means that the solution you opened is versioned, such as Team Foundation Server (TFS). To work with version control functions, you need a special version of the visual studio.
It seems (assumption based on the error message) that you can use the source from the project, you can create and run the program, but you cannot make any changes to the version repository.
The TFS wikipedia page pretty well explains what TFS is: http://en.wikipedia.org/wiki/Team_Foundation_Server
If you work with the code for yourself, this should not be a problem. If you are working on a team project using TFS as a version control system, you will have to upgrade to another version of VS.
Perhaps this thread may help you a little: Connect Visual Studio 2010 Professional to TFS
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