I just did a clean install of Visual Studio 2008 on a new machine and I don't see the File > Source Control menu option. Microsoft Visual Studio 2008 Team Explorer Version 9.0.21022.8 is installed, and I have connected to my TFS server through the Team Explorer tab on the right.
Any ideas?
Found it. After attempting to open the project from the Team Explorer pane, I got a message saying that "TFS is not your current Source Control plug-in. Click here to specify".
This brought up the Tools > Options > Source Control > Plug-in Selection dialog where I was able to specify 'Visual Studio Team Foundation Server' as the current source control plug-in.