Nooo, each time a user views a video it is streamed back to there computer. They cant save it or edit it. To watch it again it they would have to go back to the page and stream it back again.
I have done this before for a company I used to work for. Have a look here
http://www.citycentrehotels.com/Dubl...?section=video the video at the bottom is streamed via Flash Media Server. You download it into a temp folder and it means you cant save or edit the video. With this option you can then build a members area around it and secure it for member only access.
To use .wmv you will find there are alot more cost involed. There is a heavy price tag with using .wmv, have a look at using .flv its alot cheaper.