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"?

1. Install Team Foundation Sidekicks. It's free.
2. Open the Workspace Sidekick, click Search, and select your workspace from the list.
3. Click the blue computer icon to Update Workspace Computer Name and you're done.