I want to share a real time scenario which I faced in Visual Studio 2013. Suppose we have made some changes in .cs files from outside the application i.e. not modified from Visual Studio 2013.
Let say I modified 50-100 files using
 Beyond Compare  or replaced some data in files (e.g. assemblyinfo.cs)  using 
TexRep  then If I want to check in those files in TFS then I cannot see it in pending changes.
So the issue is I am not able to view files checked-out in pending changes list which I have modified from outside the source editor. Visual Studio 2013/2015 will not detect it.
 
But in Visual Studio 2010 I use to do this activity. In Visual Studio 2010 I use to this in following steps:
Visual Studio 2010 TFS Check-out files modified from outside
- Take the solution offline and close it.
 - Make changes from outside (using Beyond Compare, TexRep, NotePad++ etc)
 - Open solution and go online it will scan the changes made offline and open a pop-up displaying list of files modified. But in Visual Studio 2013 it is not available. To resolve this I have done following things.
 
Visual Studio 2013/2015 TFS Check-out files modified from outside
In TEAM menu no option available for taking solution offline.
![]()
So I have resolved this issue by installing a Visual Studio Extension.
- Go to Tools menu --> Extensions and update
 - Click on online option and search for TFS go offline. 
 
  Download & install this extension. It will ask to restart the Visual Studio. Restart it. You can see that now this feature is available in TEAM menu.
  ![]()
To go offline click on it. Now it will be offline.
![]()
 Now to go online on TFS click on File Menu
à Source Control 
à Go Online
   603