Sometimes it is possible that after you have done a full install of VS2008 with Team Explorer, than you can’t create a new project.  The only thing you could do is creating a new Team Project.

Mostly this happens when the installation takes a long time.  Internally the installation goes in timeout then.

Instead of re-installing your VS2008, you could also use following tip:

Follow this path

            Tools à Import and export settings à reset all settings

If you have done this, reboot your PC and restart VS.  You will see that you now can create not only new Team Projects, but also standard Projects.