INFO: MSXML 3.0 Service Pack 2 Installs Only in Replace Mode

Microsoft XML (MSXML) 3.0 Service Pack 2 (SP2), or later service pack, installs only in replace mode. This release is also included with Microsoft Windows XP, Microsoft Internet Explorer 6.0, and Microsoft Data Access Components (MDAC) 2.7. Replace mode indicates that the newly installed version of MSXML replaces an older version and becomes the default XML parser.

If you install MSXML 3.0 SP2 or any of the programs listed at the beginning of this article, the registry setting of InprocServer32 for CLSIDs registered by the Microsoft XML 2.0 and Microsoft XML 2.5 parsers (Msxml.dll) is reset to use the Msxml3.dll file. The MSXML object creation process with corresponding ProgIDs will use MSXML 3.0 SP2. The InprocServer32(Default) registry keys for the following classes are changed with this new install, which previously had the default value of Msxml.dll.

Programs that use MSXML 2.5 (Msxml.dll) or earlier may require additional compatibility testing with this upgrade. MSXML 3.0 is more compliant with W3C standards and stricter in enforcing the W3C specifications -- for example, in checking the valid character range.

For additional information about how to check the valid character range, click the article number below to view the article in the Microsoft Knowledge Base:

In versions of MSXML earlier than MSXML 3.0 SP2, you must run the Xmlinst.exe utility for the replace-mode change. If you run this utility under some scenarios, this may cause instability in the system and result in an unsupported configuration.

To meet the increasing demands from customers and XML developers, MSXML 3.0 SP2 was fully tested in replace mode with Window XP, MDAC 2.7, and Internet Explorer 6.0. This version installs and runs only in replace mode and is fully supported by Microsoft.

Additionally, there are added benefits to installing MSXML 3.0 SP2 in replace mode. For example:

• When you install MSXML 3.0 SP2 in replace mode, this makes Internet Explorer 6.0 an XSL Transformations (XSLT) and XPath-enabled browser out of the box. Extensive support for the W3C XSLT and XPath standards were added in MSXML 3.0. Users can use Internet Explorer as a convenient tool to display and transform XML data.
• MSXML 3.0 SP2 provides much richer client-side support for XML processing (for example, parsing, XSL transformations, and XPath support). This permits XML developers to offload the XML processing from the server side to the client side, and in this way harness the power of Internet Explorer.

For additional information, click the article numbers below to view the articles in the Microsoft Knowledge Base: