i downloaded a windows 7 professional free edition from msdn for students via my college link . now its asking for product key and activation . can anyone help me how do i get the activation key?
If legitimate, your school tech support (as they had the posted link and are managing the program with MSDN) can help you with this.
BTW, there are no "free" editions, someone paid for a license for you to use, even if it was the school as part of its relationship with Microsoft.