As media player is a Microsoft windows issued/installed program I would expect updates or warnings about this to arrive through the Windows update service, ie they would be installed automatically (assuming you have this function turned on in windows).
If on visiting the forum you have this message then I suspect it is through the advertising which appears at the top of the pages and therefore the site you were directed to was not a genuine MS update site. WOT then picks this up as a suspect site.
As the forum is a free piece of software it is subsidised by the advertising, running a HOST file (in my experience) has removed all the banner adverts. I know some other members run ADBLOCK PLUS and this also stops the banners appearing, remind me next week and I will sort something out to stop the problem occurring for you.
Geoff