How to install PDMWorks Add-In

I just installed Solid Works 2008 SP3.1. I also installedPDMWorks on to our server. I can connect to the PDM server usingSolid Works Explorer but it says I can only check in solid worksfiles through the Add-In inside Solid Works itself.

However, the PDMWorks Add-In does not show up in my add in menu. Isthis add-in an extra option I have to buy or did I not installproperly?

Thanks
ShawnSolidworksWorkgroup Pdm