How to update TFS workspace after computer name changes

I renamed my computer name, and now my TFS workspace is broken in Visual Studio 2012.

When I type:

tf workspaces /computer:ABOTONJIC-PC /owner:* /format:detailed

Workspace  : ABOTONJIC-PC
Owner      : wrongowner@test.com
Computer   : ABOTONJIC-PC
Comment    :
Collection : netuse.visualstudio.com\DefaultCollection
Permissions: Private
Location   : Local
File Time  : Current

But I need to have :

Owner      : realowner@test.com
Computer   : NEW-PC

Then I try:

tf workspaces /updateComputerName:ABOTONJIC-PC /collection:netuse.visualstudio.com/DefaultCollection

No workspace matching *;wrongowner@test.com on computer NEW-PC found in Team Foundation Server netuse.visualstudio.com/DefaultCollection.

So my question are :

1. How to update computer name in my workspace?
2. Why TFS still shows "wrongowner@test.com" in workspace although there is new email registered as "realowner@test.com"?