Working offline with TFS is different than with Visual SourceSafe.  On the one hand, VSS is better integrated with Visual Studio, so its pretty easy to unlock files for editing offline, you just begin editing them.  On the other hand, VSS can often get easily confused, and will then trot off and unlock everything in your solution.  When you go to reconnect to VSS, this can be annoying if other team members have edited files that you have checked out, but not modified.

TFS in general is better at this, primarily because its built around the concept of lock-free checkouts and the existence of far more sophisticated merge tools.  But one place where TFS falls down is the actual unlocking of files in offline mode, because it seems somewhat oblivious to the fact that these files are part of a source control system.  It just sees them as locked, and that’s that.

Turns out there’s a simple way around this, at least if you’re working with VS in a tabbed document view.  If you right click on the tab where the filename is displayed, you’ll see a context menu where the first choice is to save the file – this choice appears regardless of whether or not you have made any changes to the file.  Save the file, pick ‘Overwrite’ when prompted, and you’re off to the races.