Final Cut Pro for editing, so get a mac! 

If you're an OS bigot.
Justifying spending over a grand on a Mac just so you can run Final Cut Pro is stupid.
An old CS3 version of Premiere Pro will do you fine on Windows. I've done loads on that.
CS5.5 is a lot more stable in but it only runs in 64 bit, as already outlined.
If you just want to muck about then download the Windows Live Movie maker thing and give it a go. The thing you need to understand about video editing is that it will p*ss your time down the drain like it's going out of fashion.