Keep say wrong disk
First, are you trying to play a burned disk, like a CD-RW, or DVD-RW style disk? Sometimes certain DVD players will not play burned disks. Check your owner's manual. If you don't have one, go to the Memorex website and they may have s section where you can download a PDF version for free. Most sites do. Just type in your model number. Second, have you tried other disks, and are they ALL saying the same thing? If so, then it's possible that there is dust or dirt inside near the laser eye, and it's giving you the "wrong disk" message as an error. Try making sure that you have a clean disk, and pick the one in your collection that has the least amount of scratces/imperfections on the shiny side. If it still gives you that message, you can try either using one of those cans of compressed air to blow any dust or debris out of the DVD player and try it again. If that doesn't work, you could try a DVD Player cleaning kit, which you can get at Walmart, or Radio Shack, etc pretty cheap, then try it again. If it still doesn't work, there may be a problem with the unit itself, and you can consider making a claim on the Warranty if it's still covered, taking it in to an electronics repair shop, or just buying a new one. Hope this helps you out. Good luck!