Question:

What is the technical rationale behind the DVD region change limit imposed by Windows 10?

I understand that Windows 10 allows users to modify the DVD region of their optical drives up to five times, after which the region becomes permanently locked. I would like to know the underlying reason for this restriction, and whether it is related to the hardware, the software, or both.

Answer:

DVDs are encoded with one of six region codes, which are designed to restrict the playback of discs to specific geographical areas. For example, Region 1 covers the United States and Canada, while Region 4 covers Australia and New Zealand. The purpose of this system is to protect the rights of film distributors and prevent piracy and unauthorized copying.

However, this also means that DVDs from different regions are incompatible with each other, unless the DVD player or drive can switch between regions. Windows 10, like previous versions of Windows, allows users to change the DVD region of their optical drives up to five times, after which the region becomes permanently locked. This limit is not imposed by Windows itself, but by the firmware of the DVD drive, which is the software that controls the hardware functions of the device.

The firmware of the DVD drive stores the number of region changes and the current region code in a non-volatile memory, which means that the data is not erased even when the power is turned off. The firmware also checks the region code of the inserted disc and compares it with the current region code of the drive. If they match, the disc can be played. If they do not match, the user is prompted to change the region code of the drive, which will reduce the number of remaining changes by one. Once the number of changes reaches zero, the firmware will not allow any further changes, regardless of whether the user reinstalls Windows or moves the DVD drive to another computer.

The technical rationale behind this limit is to comply with the specifications of the DVD Forum, which is the international organization that defines the standards for DVD formats. The DVD Forum requires that all DVD players and drives must support region codes and enforce the region change limit. The DVD Forum also licenses the use of the DVD logo to manufacturers who follow its specifications. Therefore, if a DVD drive does not implement the region change limit, it will not be approved by the DVD Forum and will not be able to display the DVD logo on its product.

In summary, the DVD region change limit imposed by Windows 10 is not a software restriction, but a hardware restriction that is determined by the firmware of the DVD drive. The firmware follows the specifications of the DVD Forum, which mandates the region change limit as a way to protect the rights of film distributors and prevent piracy. Users who want to play DVDs from different regions without changing the region code of their drive can either use a region-free DVD drive or player, or use a software that bypasses the region code, such as libdvdcss . However, these methods may violate the terms of use of the DVDs and the DVD Forum, so users should exercise caution and discretion when using them.