Need help asap with Microsoft Word?

I am currently taking online classes and today was the first day. My professor emailed me the course schedule, syllabus ect and it is only available to open in Microsoft Word 2007 or better and i currently have Microsoft Word 2003. I have tried to download their Microsoft VIewer and it hasn't worked, I tried to update my Microsoft Word and they wanted me to pay 150$. I dont mind paying a little extra but not much if any. Could someone tell me what to do please.