I have been receiving the same message for a couple of weeks on one of
my desktops running Windows XP. My research indicates this is a "bona
fide" update to one of several media programs - in my case "Windows
Media Player Classic." Not a Microsoft program. The update to these
programs became available early in February and so the "automatic
update" feature of the original program has been activated. The program
to which the update is referring should be installed somewhere visably
in your system, probably in the "Programs" folder (XP.) Essencials is a
correct Spanish spelling and appears in some texts. For better
information than I can give see: 'Windows Essencials Media Codecs Update
Service : Windows Vista Setup : Windows Vista IT Pro : Microsoft TechNet
Forums'
(
http://social.technet.microsoft.com/...-928be4441949/)
I'm a novice so just for what its worth.
--
dogsticker