is already mapped in workspace or removing other's working space

The path C:\Projects is already mapped in workspace PC123;DOMAIN\USER

tf workspaces /computer:PC123 /owner:* /format:detailed

And – sure enough, it looks like there’s another workspace for a different user profile – with the same PC name (PC123).
tf workspaces /computer:PC123 /owner:* /format:detailed /server:http://tfs:8080
================================
Workspace: PC123
Owner : *ME*
Computer : PC123
Comment :
Server : tfs.domain
Working folders:
====================================
Workspace: PC123
Owner : *SOMEONE-ELSE*
Computer : PC123
Comment :
Server : tfs.domain

Working folders:
$/AAA: C:\Projects
$/AAA/BBB/CCC: C:\Projects\AAA\BBB\CCC
Not sure how/why this has happened – perhaps a duplicate PC-NAME ?

Anyway – here’s the command to REMOVE the baaad workspace – clear it out all and start again.

tf workspace /delete PC123;other-user /server:http://tfs:8080
A deleted workspace cannot be recovered.
Workspace ‘PC123′ on server ‘http://tfs.8080′ has 0 pending change(s).
Are you sure you want to delete the workspace? (Yes/No) Y