Help: XP antivirus program??

Out of no where I'm told that windows XP antivirus needs to be updated and has found viruses on my PC, the thing is I have never heard of XP antivirus and now I have two extra weird folders in my programs files and it has nixed some default things like the ability to set desktop background and appearence when I right click the mouse. Is that a legit M$ program and if it is how do I get rid of it and its folders. It won't uninstall nor can I delete the extra folders. BTW they are named rhc1muj0e34l and RichVideoCodec. Anyone ever heard of them? Help.