To open a project or solution which has already been added to the repository, but is not on your local machine:
Open Visual Studio
From the File menu, choose the Open From Vault Professional menu item.
Browse the repository to find the solution or project file that you wish to open.
If no working folder has been set for the folder containing the solution, you will be prompted for the disk location to put the project or solution. If a working folder is already set, the project will be downloaded to that location and opened.
To open a project or solution which has already been added to the repository and is on your local machine, click on the solution or project file on disk to open the project. You will be prompted to log in to the repository.