Compatible DVD Decoder is Not Installed
On most Windows operating systems, the pre-installed Windows Media Player performs barely acceptable compatibility for playing back videos, music, and DVDs. Unsupported videos will not be recognized by Windows Media Player, and instead of proper playback, there’ll be some error messages generated upon loading.
And that’s what’s going on with our "Compatible DVD Decoder is Not Installed" issue here. When you inserted some DVD you fancy enjoying with your Windows computer, you opened up your Windows Media Player and tried to load the DVD into it, yet a frustrating message pops up saying "Windows Media Player cannot play the DVD because a compatible DVD decoder is not installed on your computer".
That issue puts down to your Windows Media Player lacking of an essential video decoder to decode DVD videos, while decoding is a necessary process for a media player program to read and play specifically compressed video files.
(Try updating or reinstalling the DVD decoder on your PC, if you already have one.)
To make WMP play any DVD you want without a hitch, it takes either additional codec installation to make Windows Media Player more compatible, or we can do something with your unfriendly DVDs. There are three solutions with a detailed tutorial apiece provided in the following to solve your problem. Let’s go through more details.