infected message

Giganews Newsgroups
Subject: infected message
Posted by:  gsf suzie (gsf_suz…
Date: Wed, 6 Sep 2006

Since switching my pc on this evening, a yellow bubble keeps popping onto
screen on bottom right saying that my computer is infected and that windows
has detected spyware. I am using windows xp home and have norton 2006 and
have scanned my pc with no results. What do I do to get rid of this annoying
bubble and might I have an infection? I'm a complete novice with computers,
any help appreciated.