TFS Source Control

Team Foundation Server (workgroup edition) is installed on my laptop (Windows Server 2003) and afterwards I installed the trial edition of Visual Studio Team System, but I could not add projects or solutions to the Team Foundation Source Control in my Visual Studio IDE. Connecting to my Team Foundation Database on the other hand (Team Explorer) was not a problem. Apparently the source control plug-in was set to None. I cannot remember that this was also the case with my previous installation of Team Foundation Server. Team Foundation Source Control was set as the default source control plug-in ...