When trying to map a local folder to a TFS server as a different user than the one under which I was logged in, I kept getting the message:
1 The working folder [source path] is already in use by the workspace [workspace name];[owner] on computer [tfs server].
I was finally able to map the folder by first deleting the local workspace as the logged in user:
1 tf workspace /delete /server:[tfs server] [workspace name];[owner]
Note that the “owner” was the currently logged-in user.
This post was migrated from https://blogs.msdn.microsoft.com/rob/2012/10/13/solved-the-working-folder-is-already-in-use-by-the-workspace/.