Plug and Play in Windows doesn’t work. I get an error message that I have a ‘missing decoder’. How do I resolve this issue?
"Missing Decoder" usually means a codec is missing when playing videos (e.g. in Windows Media Player), in which case, follow up the article Alan W points to or download and install the K Lite Codec Pack from http://www.free-codecs.com/download/k_lite_codec_pack.htm.
"Plug and Play" is a different technology that has to do with automatic detection of hardware devices and matching them up with device drivers. I take it you did not mean that, but if I'm wrong, please provide more details.
plug and play of what dvd? what you did prior this problem?
Read this article from LifeHacker : http://lifehacker.com/278576/install-missing-codecs-with-codecinstaller
It will point you to a handy app called CodecInstaller that will help to solve your problem.