I haven't had any problems with Word 2007 for ages but then I needed to change the template used by a document I was writing. In Word 2003 and previous, this was the Tools and Templates option on the Tools menu I think. Two clicks and you're there. Why couldn't it be the same in Word 2007? Oh yes. Just a ribbon.
So then for future reference, here's how you change the template for a document.
Open the main Word menu. That's the round button in the top-left of the Word window to you and I.
Click Word...