Don't you dare rename all your files.
Word uses a file called normal.dot as its default template. When Word is first installed and you haven't run it yet, you won't find that file. It is created whenever Word can't find the existing file. The normal.dot template commonly goes bad. All you have to do for Word NOT to recognize the file and to have Word create a brand new, shiny clean one, is rename (or delete) the one that already exists. Many people have more than one on their PC, but in different directories. Rather than go through finding out which one Word is actually using, just rename or delete ALL files on your hard drive with the EXACT name of normal.dot (notice the T and not the C on the .DOT part).
Make sure Word is closed.
Hit Start-Find-Files or folders.
Type in normal.dot and hit enter.
If you find any, just delete them.
Now, relaunch Word, which might take a second or so longer to launch then usual because it has to create a new normal.dot file for you.
Hopefully, you'll be all set.