Why would a DVD not play on your computer?

The answers to this are many and varied. But let's start with the basics...

Firstly, is the drive, DVD compatible? A standard CD drive will not play DVDs. A DVD drive will however play both.

If it is a DVD compatible drive, will it fail to play any DVD, or is it just one particular disk? If only one disk, then that disk is either damaged or faulty or of the wrong region (see below).

If it won't play a DVD at all, then suspect either a faulty drive and/or hardware. If they're okay, then the installation of the drivers and supporting software maybe at fault. Uninstall the software/drivers etc., remove the drive and re-install again.

Finally, is it the right region? Some DVD drives are multi-regional, which means they will play DVDs from other regions (countries).

Others are multi-regional, but only for the first few transitions: you are allowed to play disks from different regions for up to 4 or 5 region changes. On the 4th (or 5th) region change, that disks region will be set as the region for the drive - permanently! A pointless feature, in my opinion.

The regions are as follows...

0 All regions 1 United States, Canada and US territories 2 Europe, South Africa, Middle East, Japan 3 South-East and East Asia 4 Central America, Mexico, S. America, Caribbean, Australia, N.Z., Pacific Isl. 5 Rusland, former Soviet Union, North Korea, India, Africa 6 China 7 Reserved (not active) 8 International territory (ships, planes etc)

AnswerWhere the answer states: "If only one disk [won't play], then that disk is either damaged or faulty or of the wrong region (see below)", I'd like to point out that there is another reason not mentioned in that list -- the programming of the DVD can prevent it being played on various computer DVD drives. Sometimes the drive will not even "see" the disc because of this. AnswerWith the advent of copy protections for DVDs, there are an increasing number of production firms that are specifically coding discs so that they will not play in a computer. These firms instead are offering "digital versions" that can be purchased for a premium. Disney and its subsidiaries are at the forefront of this movement.