According to APC Magazine, Microsoft have cut out the ability to play HDCP content (blu-ray & HD-DVD) on 32 bit versions of Vista.
By far the majority of PCs use 32-bit processors, because despite AMD's efforts to push 64-bit CPUs into the marketplace early, Intel's first widely-promoted 64-bit CPU is the just-released Core 2 Duo.
PC users will now have to choose between a PC that can play high definition content (64 bit) versus one that can potentially run older devices that only have unsigned drivers available (32 bit).
"Signed drivers" are ones that have undergone a Microsoft quality-assurance process and received a digital certificate that certifies them as stable for installation on 64-bit Windows.
Microsoft's move to drop support for playback of studio-released HD movies on Vista is likely to anger the large number of people who were hoping they could use their existing 32-bit PC with an upgrade version of Vista.
The surprising disclosure was made by Senior Program Manager Steve Riley during a presentation on Windows Vista security at Tech.Ed 2006 Sydney today.
View: APC Magazine Story
