I use camtasia - it's good for editing webinars that sort of thing
Can it convert videos to slow motion? And allow you to insert separate audio?
Yup!
Does anybody know any good free movie editing software, or even some good inexpensive ones. Windows movie maker does not work on my comp for some reason. I basically need to be able to make a video go in slow motion.
Cyberlink Power Director. I use it a lot, pretty intuitive, easy to upload finished product to social media (youtube etc...) slow mo no worries. Not free software, but pretty cheap compared to some others. Or just download pirated version from piratebay.http://www.cyberlink.com/products/powerdirector-ultra/features_en_AU.html?&r=1