This message appeared on the heidi eraser website so I assumed it was legit. Then it appeared again today on another website. it was not a popup more like a windows webpage message popup. (Hard to explain) Is this malware? Does windows media player have downloads it seems it would be in windows update.
ando35, perhaps a review of Remove “This content requires Media Player 12.2 Update” (Virus Removal Guide) could help you.
Nothing can be guaranteed to be 100% effective all the time. Follow the removal instructions, and hopefully, you'll get rid of it. Best of luck!