Hi,
1. Have you made any changes to the system?
2. What is the latest make and model of your player?
3. Are you connecting the blue ray player through Wi fii or through USB port?
4. What is the complete error message?
Check in device manager if the drivers for the player are installed. Follow the steps below:
1. Click on start and type device manager in the search bar and open it.
2. Check for your device and see if there is any exclamation mark against it.
Update the latest drivers for your player and also any related supporting software.
Also try running the hardware troubleshooter. Refer the link: http://windows.microsoft.com/en-in/windows/troubleshooting-windows#troubleshooting-windows=windows-7
You may also refer to the link: http://windows.microsoft.com/en-in/windows7/open-the-playing-and-burning-cds-dvds-and-bluray-discs-troubleshooter
Note: if you are using a Pioneer player, then it is a known issues with their devices. Please check with them on their support forums.
Hope this helps.
Thanks!