windows moviemaker is VERY good for a free program. I even use it when I don't want to fool around with premiere or can't get to a mac to use FCP.
even if you got a hold of a "better" program, the output is dependant on the user's knowledge, experience, and comfort with the program.
the super high quality programs are NOT free, and if you have no idea what you're doing, you'll probably end up with a WORSE result than with Movie Maker since the program is that much more complicated.
I second harley2ride's response. look up some tutorials, read help files, and play around with movie maker to familiarize yourself with the capabilities of the program and your videos should vastly improve.