| Home | Table of Contents | Please view with Internet Explorer (version 5.00 or higher) and enable scripting. For reasons, see Browsing This Web Site. |
CURRENT WORK ITEM - PREVIEW ONLY
The IsOS function supports OS_DATACENTER as its dwOS argument in various builds of SHLWAPI versions 5.00 and 5.50 (see below), and then from version 6.00. However, these versions appear to address entirely unrelated questions about the operating system.
For those builds of versions 5.00 and 5.50 that support OS_DATACENTER, the function returns TRUE if
For version 6.00, the test is changed to
except that the implementation in Windows XP Service Pack 2 tries to have it both ways: if the operating system version is 5.00, it applies the earlier test, otherwise the later.
The OS_DATACENTER case of the SHLWAPI function IsOS is available in version 6.00 and higher. An earlier, but different, implementation is known in the following builds of versions 5.00 and 5.50:
It is explicitly not supported by the following other builds of versions 5.00 and 5.50:
Use of OS_DATACENTER seems rare. One use that Microsoft is known to have found for OS_DATACENTER is in many but not all builds of SHDOCVW.DLL version 6.00, for a feature that may first be seen through an Internet Explorer dialog box:
This feature (or, rather, Microsoft’s particular design of it) requires Windows Media Player 7 or greater. If you click Yes but Windows Media Player 7 or greater is not installed, then SHDOCVW will tell you (if your operating system is Windows XP or greater):
This may be primarily a ruse by which one Microsoft application that dominates its market gets to advertise a Microsoft application that still has competitors, but if the operating system is anyway not sufficiently capable for Windows Media Player 7 or greater, then SHDOCVW does not bother offering the Media Bar, let alone suggesting that you try (pointlessly, as it would turn out) to install Microsoft’s media player.
Necessary (and documented) conditions for the Media Bar are that the operating system be at least Windows 98 or Windows 2000. See, for instance Media Bar is Unavailable on Internet Explorer 6 for Windows NT 4.0. However, there are three ways that an otherwise acceptable system can be ruled insufficiently capable for Windows Media Player 7 or greater. One is that it satisfies the OS_DATACENTER conditions.
This tie between Internet Explorer and Windows Media Player is withdrawn from SHDOCVW version 6.00 starting with Windows XP Service Pack 2. Perhaps it just passed its usefulness or was frowned on by some regulatory authority, but it is curiously contemporaneous with when Microsoft seems to have noticed that OS_DATACENTER is ill-defined, having meant very different things at different times.