Eventually I could figure it out. I explain it here for the good of the public.
Shortly before the problem with WORD started about three weeks ago few messages about some license expiration came on the screen for a fraction of a second; I could not read them.
Two days ago I received an update from "Acrobat." After installing it a small window would open on the top left corner of the "Outlook" program and would not go away. Calling the "Acrobat" I found out they no longer support MS Office 2003 and "Acorbat 8 standard" which are the softwares I have on my HD. Nowadays they are into MS Office 2010 and Acrobat 10 according to their Helpdesk.
The final and practical solution for the time being was un-installing the "Acrobat." As soon as I did that the problem with WORD disappeared. I do not need the "Acrobat" anymore so my problem is solved.