A family of Microsoft word processing software products for creating web, email, and print documents.
When you don't have Word running, use Ctrl+Shift+Esc to display the Windows Task Manager Processed tab and check to see if there is an instance of WINWORD.EXE in the list. If so, select it and then click on the End Process button.
Also, make sure that there is no "left-over" lock filed ~$Normal.dotm in the templates folder or another Normal.dotm in some other location on the computer.