>HI!
>I user that left the company has checked out a project file.
>
>I tried to change my machine name to this user and log in as this user but the user has been deleted from the system.
>
>How can I uncheck -out this project...

The admin of VSS has all the rights to this.
If you login to VSS as Admin and try to 'Undo check Out' on the file in question, you'll get a message box telling you that this file is checked out by somebody else and aks you if you want to proceed.

Regards,