One more post about MSXML6 SP2, XP SP3 and SQL Server : I've been duped!
Microsoft delivered a KB article about this whole MSXML6 problem with XP SP3 (which I talked about recently here and here), but it is NOT the KB article I was hoping for, nor anything resembling the article I had been promised. Instead of finally supplying and documenting the mythical registry fix required to let SQL Server setup bypass the MSXML6 problem, they simply made official the workaround of using the Windows Installer Cleanup Utility to clear the path for setup to lay down the same bits again. You can check out the article here, but there really isn't any news that hasn't already been broken elsewhere:
Maybe they just really want you to upgrade to Vista (or make the wait for Windows 7 that much more intolerable).