"Try one more time just to make sure-- I think you're on the right track. The file you need to register is armatthumb64.dll-- don't bother with the other one. It must be run from an elevated command prompt.
Try the following:
Thanks for the reply. I did what you said below and when I try to open the file I am getting the following message: The module"ArMaterial Thumb64.ddl" was loaded but the call to Diregister Server failed w/error code…"