Applications :: Word Files Will Not Open From Directory?

Mac Word 2004 for teachers/students was working smoothly for me until the last month. It seemed as though the problem started when I tried to open (by mistake) an excel doc in Word - or vice versa. Now, Word will not let me open a file from the directory. (It will let me select the recently opened docs on the drop-down menu.) When I click "File" and "Open", the screen freezes and eventually pulls up a white screen with lines on it - looks like a writing tablet, which is the edition's logo - and it says "Open" on top.