This is the forum for Word, including Word 2003, although many of us are using later versions. It is surprising how many of the quirks remain the same.


Your profile says Office 2010 and Windows 7. Is that mistaken? The error message box looks like something from Windows 11.



Many error messages in Word are misleading or triggered by something that should really give a different message. However, this one may mean that another instance of Word is open. Check your Windows task manager.