We use Group Policy to update our labs. Normally we turn off automatic updates on those machines because users in the labs are not going to have installation privileges. When we pushed out SR7 V-Ray for Rhino 1.5 stopped working, giving a “missing .dll” error. What we think happened is that SR7 created a new Program Files folder (“Rhinoceros 5.0” where the previous installation was in “Rhinoceros 5.0 (64-bit)”) and V-Ray for Rhino 1.5 had installed a set of .dlls in the old Rhinoceros 5.0 (64-bit)/System folder. While the registry key for the plug-in was moved, V-Ray no longer could find the .dlls because the old System folder was emptied. When we added the set of missing .dlls to the new System folder, things worked again.
I suspect the addition of plug-in files to the System folder is a “bad practice”, since the installer isn’t going to be smart enough to know what to do; that’s a Chaos Group issue. At the same time, changing an installation location is going to mean some clean-up, since any Start Menu items that linked to the old spot were going to break (it’s not unusual for lab environments with lots of software to not use the default Start Menu items created by the installers since it leads to an extensive and functionally disorganized list of applications). It would have been useful to have an installation note about the location change, although it’s possible the folder location was changed in an earlier Service Release which we did not install and there were some notes there about it.