The 'Disc read authorization' or 'disc read authentication' error is oftentimes caused by the existence of Drive Letter Access (DLA) software on your machince. DLA software includes DVD recording applications with the ability to drag and drop files directly to a drive letter, such as Sonic or Roxio. These applications are known to cause disc authentication problems. To fix this issue, try the troubleshooting steps below:

• Click on the 'Start' menu on the Windows Taskbar.
• Click on 'My Computer.'
• Right-click on the DVD drive letter you are using to run your game.
• Select 'Properties' from the list of options.
• You should see a 'DLA' tab in the Properties panel, where you can disable the DLA software on your machine.

If disabling the DLA software from the Properties panel does not solve your issue, you can also try to update the drivers for your DLA software through the manufacturer's website.

If updating your drivers still causes you to get the 'disc read authentication' error, you might want to completely uninstall your DLA software using the 'Add or Remove Programs' tool in the Control Panel.

Update: Many of the reports we have received regarding this issue all list the 'MATs***A DVD-RAM UJ-841S' as the existing DVD drive in affected systems. The Mats***a drive is usually found in Toshiba laptops. We recommend checking the Toshiba and/or Mats***a support websites in order to find a more targeted solution to this issue.

You might also want to consider updating your Toshiba drivers by visiting this site and selecting your machine's make and model.

CD Emulation software is also known to cause similar issues with disc authentication. Below is a list of software that is known as, or known to include, CD Emulation Software that could potentially prevent the game from playing properly:

• Fantom CD Emulator
• Alcohol 120%
• Nero Image Drive
• Phantom CD
• Clone CD
• Ark Virtual Drive
• Veritas DLA
• Daemon Tools

If you are unsure about how to turn off emulation settings, consult your emulation program help files. If you have emulation software not listed above that does not provide adequate information about how to turn off emulation to avoid software conflicts, then uninstall the software from your machine.

If Alcohol 120% is on the machine:

• Start Alcohol 120% and go to the Emulation Options.

• Select Emulation from the options tree. Uncheck the Ignore Media Types box to turn off the media type emulation, exit Alcohol 120%, and restart the game application.

• Select Extra Emulation from the options tree. Uncheck the BAD Sectors Emulation to turn off this type of emulation, exit Alcohol 120%, and restart the game.

If CloneCD is on the machine:

• Look on your task bar at the bottom right of your screen (next to the clock). Locate the CloneCD tray icon, which can be a picture of two CD-ROMs; or of a sheep's head . Right-click the icon and make sure Hide CD-R media is un-checked. Restart the game application.

If Daemon Tools is on the machine:

• Select the icon at the bottom of the status bar of windows.
• Find the Daemon Tools Icon
• Right Click on the Daemon Tools icon in the Task Bar.
• Select the Emulation tab.
• Deselect SafeDisc.