|That pop-up does not indicate a virus or anything malicious. It's often seen with various applications. I've had it myself and in my case it was caused by some free software being "buggy" so I uninstalled it.|
In your case, if you can't manage without RealPlayer, try uninstalling it, then re-install.
However, these days it's perfectly possible to use your PC and the internet to it's fullest extent without having RealPlayer installed as there is much less RealPlayer content on the web now. I don't even have QuickTime installed for the same reason.
You can download YouTube content with Firefox using a Firefox add-on, and FLV players are freely available for playing them once they've been downloaded.
I haven't had RealPlayer or QuickTime installed for over ten years now, even though I'm constantly playing web-based multimedia content.