Navision attain 3.6 & Windows installer

Hi, I have set-up Navision Attain 3.6 to run on Metaframe Xp. Everytime the users log in and when they change company the installer runs. I have heard that a manual installation is needed and the Dlls need to be registered manually. Can anyone provide me with a bit more info (or even better a solution). Cheers Toad [:(]