Windows Vista will not have support for really old DVD drives. (The information below was kindly provided to me by the optical storage driver team.)
Windows Vista 对于一些特别老型号的 DVD 光驱已经不再提供支持了。（以下信息由光存储驱动开发组友情提供。）
When PC DVD drives first came out in 1998, the drives themselves did not have support for region codes but instead relied on (and in fact the DVD specification required) the operating system to enforce region coding, with the further understanding that starting on January 1, 2000 all newly-manufactured drives would support region coding in hardware rather than relying on software enforcement. For the purpose of this discussion, I will call the two types of drives “old” (manufactured before 2000) and “new” (manufactured on or after January 1, 2000).
1998年，PC 上的 DVD 光驱刚刚出现的时候，光驱硬件自身并不支持区码限制，而是依赖操作系统来确保这个限制（实际上也是 DVD 标准所要求的），不过在后来更新的标准中，自2000年1月1日起，所有新生产的DVD光驱都应当在硬件、而不是在软件中确保区码限制。为了讨论方便，接下来我将这两种光驱称作『旧』光驱（2000年以前生产）和『新』光驱（2000年1月1日起生产）。
It is that software enforcement that is going away. Turns out that the enforcement of region coding in software had its own problems:
- It was impossible for third-parties to compile their own CDROM.SYS from the source code in the DDK because the region code enforcement code was not included in the DDK.
第三方开发者无法从DDK（驱动程序开发包）的源代码中编译他们自己的 CDROM.SYS，因为 DDK 中没有区码限制相关的代码。
- The region code enforcement code would sometimes mistake a new drive for an old one, resulting in customers unable to play DVDs. Even worse, the driver test team could not reproduce the problem reliably, and the problem went away entirely once a debugger was attached to the system.
- The code to support the older drives is complex, and the drives that the optical storage team purchased prior to January 1, 2000 are dead or dying. Consequently, testing the code that provides support for old drives has become increasingly difficult, and when the last old drive finally gives up the ghost, testing will become impossible altogether.
These were among the considerations which contributed to the decision to stop supporting these old drives.
What does this mean for you? Almost certainly, the answer is “absolutely nothing”.
First, there is no change to the way data is read from DVD drives, so data discs will still work the same way as they do today. Second, all new DVD drives will continue to run as they did before; the only change is that the risk of mis-identification as an old drive has been removed. Only if you have an old drive will you notice anything different, namely that encrypted/regionalized DVD movies will no longer play. And since the average drive lifetime is only three years, the number of such old drives that are still working is vanishingly small. Not even the optical drive test team can manage to keep their old drives alive that long.