How to disable multiple checkout in TFS

Hi everybody,

I want to disable the TFS multiple check-out, but it looks not work.

I have do the following options in the multiple workstation:

1. Within Team->Team Project Settings->Source Control...->Check-out Settings Tab I changedEnable multiple check-out to be unchecked.
2. Within Source Control Explorer->Workspace Combobox->Workspaces...->Edit...->Advanced->Location I changed "Local" to "Server".

After complete above option, I have test it, I find the same file can also check out in multiple workstation.

Please help.

Thanks.