Warning! Media codec has been destroyed is a fake alert displayed by fake antispyware WinCodecPro. This “Media Codec Has Been Destroyed” alert sais:

“WARNING. Warning! Media codec has been destroyed. Risk of losing all your audio video files high. To resolve this issue, update your media codec immediately.”

It advices you to update media codec, but everything what you have to do is to find and remove fake program called WinCodecPro.

Source: http://www.spywares-remove.com/warning-media-codec-has-been-destroyed