In Firefox, I select Tools > Add-ons > Find Updates. The Plugin Check page comes up in the browser. The entry for the WMP Plugin indicates it is out of date. I click on the "Update" button and nothing happens. When I mouse over the button, no link is indicated in the status bar (it continues to read "Done"). The entries for the other plugins indicate they are current. When I mouse over the "Up to date" button for each of those entries, a link is indicated in the status bar. I am running Windows XP SP2 on a 2005 Dell Inspiron 6000 (1.6 GHz Pentium M processor, 590 MHz bus, 504 MB RAM). I have Norton Internet Security 2010 installed and running.