Well for windows there are enough. It depends on the budget and how professional you want it to be.
http://jahshaka.org/ is a open source video editor, but i never worked with it so cant say how it is, but its free anyway.
For beginning/amateur editing i can recommend Sony Vegas, the work flow is so quick and i like it. It is kinda limited though for more professional editing, and its not free.
I heard virtualdub worked good as well, and its free. Just google and you find a lot more free. But im not sure if free editors are really that great. If you seriously consider doing something with editing, go for a commercial product.