I removed the WorkgroupShare server program and now cannot un-install the client.
The WorkgroupShare client program cannot be un-installed
In earlier versions of WorkgroupShare v1 the client could not be un-installed unless the server was running
Under normal circumstances, the WorkgroupShare client must make contact with the WorkgroupShare server before the Outlook add-in can be un-installed from the client computer. For this reason, we recommend that you remove all of the WorkgroupShare clients before removing the server component.
If the WorkgroupShare server has already been removed, you will need to first re-install the WorkgroupShare server and then re-install the client. The client should complain that the server GUID does not match. At this point you can un-install the client.