You have chosen to only allow certain users of this machine access to certain instances of Workbench.
This would be because you have different users using this machine and they require access to different instances of Workbench.
Open two instances of Windows explorer, one instance navigated to the Documents settings directory, the other instance to C:\Program Files\Workbench\Shortcuts
In the Documents and settings area select the 1st user you wish to setup, in this instance 'administrator'
Click on the administrator directory. If you have Administrator rights on this machine you will be able to see the following.
Select Start Menu, then Programs. In this directory add a directory called Workbench then a directory under that called Refresh.
Now go to the other Windows explorer pane and you will something similar to below
Select the shortcuts to the instances of Workbench you wish this user to have and copy them to the Workbench Directory you created in the programs directory above.
You now have to go to the directory c:\Program Files\Workbench\Shortcuts\Refresh and copy the Refresh icon for one or more Workbench instances as required
Repeat this step for very user that will access Workbench form this workstation (if more than one).