You need to renew your normal.dot template
First go to Control Panel - Folder Options - View tab and click button beside "Show hidden files and folders". Click Apply and OK.
Make sure Word is closed, and then go to Start and Search - type in normal.dot and OK. When you find one (or more) files rename it/them as oldnormal.dot
Then start up Word, and it should now be OK. The system will produce a new normal.dot file.