If you are not administrator, but you can sart/stop services (for ex. power user), you should set aawservice to manual and do bat file like this: place it to folder, where is ad-aware installed and and doubleclick it, when you want to start ad-aware. And then, if you close ad-aware, the service will be stopped. Its easy..
Arent there ANY admins or Ad-Aware developers?? They should tell us about Ad-Aware 2007 Service and what for it is and why it is in free version???! I also think it is very very unnecessarily... I am really thinking of uninstalling ad-aware.. P.S sorry for my bad english