DVD Region Clear Removal: You can remove some of the region restrictions on DVDs by using a simple "grep Region=1" and "grep Region=2" command on the boot CD you wish to unlock. Then insert the DVD into the drive. The DVD should pop up and ask you to update your anti-piracy software. Quit the program. Reboot the computer. The DVD should now show up on your computer. Perfect. If not, check your anti-piracy software in System Preferences>Security and Privacy (or look at the bottom left of the screen after you log in). If you don't have any region locking, this is just a way to guarantee that you're playing any DVD you buy in trusted territory.
Hardware Region Lock Removal: Some DVD players don't support region locking. Hardware region locks can (for example) be unlocked using a USB connection (read USB drive) that contains a DVD of greater width than that intended by the company that manufactured your DVD player. DVD drives older than the Philips DVD-R/RW drive will not play DVDs without region clearing. The Starz DVD-R/RW drive for example, is one such. There are a few different hardware region locks and Sony is the most well known. Other companies that have region locks, such as Diamond, are not the same thing. They are simply a smaller companies that want to stop piracy and as such follow the industry trend of trying to clone the same things as the others. This will throw up errors when trying to play a region-locked or region-free DVD on the region lock's DVD player. Some DVD players will still play the DVD but it will display a warning message that you have a region lock that DVD may not play on your DVD player. There are some models of the Sony DVD-R/RW and DVD-RW drive that are compatible with region locking and not compatible with region clearing. And there are many other DVD players that should play region-free DVD.
Software Region Lock Removal: A text-based step-by-step process can help you remove region locks using software without a DVD drive. First, you'll want to replace the DVDs that players are made for. After mounting the regions-unlocked DVD, use "cd" to get to the correct directory on your computer, where you have installed the DVD Regional Remover. Then, double-click on the DVD Regional Remover icon. Change the "Source" to your DVD. d2c66b5586