As the database is out on the <<middfiles>>\org\controllers files\windstar (I think I remember the path correctly) you have 2 options.
1) From the R2 box, go to the Windstar\Client Update folder and run setup. a. Disable UAC b. No Key installed c. Run as admin d. Next, next, next on the install options (not sure how many) e. Once complete, plug in the key This will install a copy of Tax Nav on the R2 box pointing to the current production data,
2) Copy the Windstar folder and all subfolders to a different location a. Run setup as above from the new location This will create a separate instance of Tax Nav talking to a copy of production that you can test with.