I've used "Any Video Converter" also for some time now. Works good for the small amount of videos I deal with. Free Also.
http://www.any-video-converter.com/p...or_video_free/
Guess it depends on how much you want your video editor to do. I've tried the Windows Movie Maker but it always seems to crash get hung up while I am almost done with a project and half to restart it over again. I've used Neros version of an editor off and on. I think it is called Nero Vision and it has atleast been more stable. I also just found a free probram that makes combining and simple editing a breeze to do. If the two files are the same resoulution and bite rate. It called VideoEditMaster I downloaded it off of the cnet a while back.
http://download.cnet.com/Video-Edit-...html?tag=mncol
I also downloaded the K-Lite codec pack like Shaun mentioned above. I was having problem between the avi mov mpeg, mpeg4, wmv, asf, vob, etc etc etc etc.....