No, iMovie is Apple-only software that comes as part of the iLife package that ships with every Mac. There are several NLE applications on the Windows platform, though. To name a few:
Adobe Premiere
Avid Media Composer
Canopus EDIUS
Pinnacle Studio
Windows Movie Maker (a basic editor that ships with the Windows OS)
Windows Movie Maker very easy to learn, much like iMovie. It doesn't have the same level of polish and integration that you get with the iLife suite of applications, though. Pinnacle Studio is what I would consider a step-up NLE, with the rest on this list being professional-level applications that have far steeper learning curves.