msxml4-KB954430-enu replaced by msxml4-KB973688-enu.exe, i have already check it. -- ADD -- I can not install MSXML 6.0 Service Pack 2 (KB973686) on XP SP3 - at all. It's really for SP2. I try install on clean system, and try to install over MSXML 6.0 Service Pack 1 - no result, installation aborted. In other hand, when installed MSXML 6.0 Service Pack 1 on XP SP3, Windows update does not provide any updates for it, critical or optional. So, IMHO, we don't need it for SP3 updates list.