I have been  come across a problem with installing addins on a Server and wonder if anyone with Server knowledge can explain why this is happening or suggest  a better way around the issue.

In the installation in question has R6 installed on a mapped drive on the Server and the addins are in the addins folder. The workstation is running under Windows 7.  When installing the addin through R6 the program requests elevated User Account Control permission. This is necessary to allow the addin dll or ocx to be registered on the workstation. However, it appears that as soon as this elevated permission is granted the workstation can no longer access the Addins folder on the Server.  This means the addin fails to register and install.

The solution was to turn off UAC temporarily and to Run R6 as Administrator. The addin then installed.

The question is what is preventing the Workstation from accessing the Addin folder when UAC permission is elevated ?