PC Audio Software for Film

Hi,

I've just hired a musician to compose some songs for my movie, but he doesn't have experience writing music to match picture. Because he works on a PC, we're having trouble finding a simple Audio editing software that allows you to watch real-time video simultaneously. Would Pro Tools be our best option? I apologize that this is a PC related question, but I was hoping that someone would know a good cheap PC alternative to Apple's Soundtrack or Logic. Any info much appreciated.

Thanks,
Alexander