|Microsoft DirectX 9.0|
It is the responsibility of the system manufacturer to select an initial DVD region for the DVD drive in their PCs.
Important Only encrypted discs can be used to set the region.
The system manufacturer can set a Registry key (HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\DefaultDVDRegion (binary)) to set the default DVD region for the drive. The value of this key should be set to the region number for which it should be set on first playback. System manufacturers using OPK builds can add this value to the registry during an "audit mode boot," so the end user never sets the initial region. If this key is set before any DVD title is played on a DVD-enabled Windows system, then the Windows components will select that region for the drive on the first attempt to play back a DVD title.
If the system manufacturer sets the default region in the Registry and then plays a multi-region disc that includes the default region, the region is set to the default and the disc just plays. If the disc's region does not match the default region, the user will be prompted to change to the required region. (This will be the only region change allowed for an RPC-1 drive.) If no such default region is specified by the system manufacturer, Windows picks a region based on the Operating System locale, time zone, and other factors. If the first disc played is a multi-region disc, then Windows picks the region based on the locale, time zone, and other factors and looks for a match with the lowest region number. If no region on the multi-region disc matches the region picked by Windows, then the region with the lowest number on disc is selected.
If the manufacturer does not set a region, on first boot the Windows 98 Operating System base components will pick a region based on the Operating System language and the time zone and set the drive to that region. The system manufacturer is free to set the region on the drive and if that is not done during the manufacturing process, it is up to Windows to select the drive's region based on the best guess it can make.
In Windows 2000, the default DVD region is selected based upon the locale that the machine is set up for. Windows 2000 will always set the initial region for a DVD drive using this default region as well as the disc's region, if there is a disc is in the drive. The system manufacturer does not have to do anything to set the initial region for Windows 2000 DVD drives.
For RPC1 drives, if there is no disc in the drive during boot up then the default region is set based only on the locale of the machine. If there is a DVD disc in the drive during boot up, the default region is selected to be the drive's region, provided it matches a region of the disc; otherwise the lowest region on the disc is picked as the initial region of the drive. The user (or system manufacturer) has one remaining change allowed, in case the default was not correct.
For RPC2 drives, if during the setup process Windows 2000 finds that the drive does not have any region set (for example fresh drive), it will try to pick a region as above, but only if there is a disc in the drive. (RPC1 drives will choose the region without any disc in drive). Once a region is set for RPC2 drives, it is not auto-changed by either a re-installation or a clean installation of the Operating System.
The registry key on Windows 2000 systems is HKLM\System\CurrentControlSet\Control\Class\<CDROM GUID>\ <instance number>\DefaultDVDRegion(binary) .