There has been what is known as a new (zero-day) exploit that attacks Adobe Flash Player. Distributed through the Angler Exploit Kit, the zero-day delivers malware that takes control of your computer to commit click fraud.
The Adobe update will not update older OS like XP.
Tat is why you are getting the messages but no update.
There is a free utility that will protect XP.
http://www.malwarebytes.org/antiexploit/?utm_source=engaged&utm_medium=email-internal-b2c&utm_campaign=EM-january2015newsletter&utm_content=mbae
That will take care of part of the problem.