During the course of trying to remove an error where Project was having trouble connecting to Team Foundation Server (TFS), I realised there was no method of removing the link between a Project file and a Team Project on TFS once it had been made.

As I wasn't seeing the updates to Iteration names I'd changed for the project in the MS Project plan, I wanted to unhook the link between Project and TFS to start it again.

The following method won't be necessary for most people, as once you have selected the link then you will be wanting to keep them locked and in sync. But in case you've selected the wrong Team Project, or want to simply unhook it, and try it again, here are the steps:

1. Close Microsoft Project
2. Open the Registry Editor (regedit)
3. Navigate to My Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\MS Project\Addins\TFCOfficeShim.Connect
4. Modify the LoadBehaviour key from 3 to 2
   This prevents the Team Foundation Client plugin from loading with Project.
   
5. Load Microsoft Project
6. Load the project file you wish to amend the link in
7. Select Properties from the File drop-down menu
8. Select the Custom tab
9. In the Properties list box, there should be entries starting with "VS Team System Data DO NOT EDIT" etc
10. Select each of these entries with a single-click (no multiple selects I'm afraid) and click "Delete" (there were 39 of them on mine, the first entry at the bottom of the list "VS Team System Data DO NOT EDIT" appears to be the total number of entries for the encrypted text)
11. Save the project file
12. Close Microsoft Project
13. Repeat steps 2 and 3 if you have closed Regedit
14. Modify the LoadBehaviour key from 2 back to 3
15. The Team Foundation Client plugin will load with Project again now.
16. Load Microsoft Project
17. Load the same project file as before
18. The "Choose Team Project" option either in the "Team" menu or on the toolbar should now be available again.

Hope this helps, Cheers, Jonathan