What brand and model is the BluRay Drive?
Try other Bd discs and see if there is a issue.
Some drives simply can not play certain discs for whatever reason.
For example, my old LG drive would not play the movie iRobot. It just wouldn't read or recognize the disc. There were a couple others but I can not recall which ones off hand. But replacing the drive with a newer one resolved the issue.
If this is the problem however, it will be easy to identify.
Just open My Computer, and look at the BD Drive after you load a disc. If it shows as empty, the drive can not read the disc and simply doesnt know theres one there. Not much you can do from here but replace the drive with a better one.
If it does show the disc in the drive, and name of it, then it could be other issues such as a HDCP problem. If this is the case, a program like AnyDVD running in the backgroud will fix it since the requirement will be nullified.