I had a strange phenomenon while installing SQL Server 2005 Express SP2 at Windows XP with Service Pack 3 installed. The installation process stopped at installing MSXML 6 and the Database Service can't be installed. Thus, the installer said that the installation failed.
I thought this one may caused by the SP2, so I tried to install SQL Server 2005 Express SP3, but the installation also failed. Strangely, if I install either SQL Server 2005 Express SP2 or SP3 at Windows XP Service Pack 2, the installation can be completed successfully. The problem only occurred at Windows XP SP3.
I tried to search at Google, the first aid for my problem :D then I found that the problem was caused by the MSXML 6 which was installed by Windows XP SP3 package. And the most frustrating thing was: I can't remove MSXML 6 using Add/Remove Programs....GREAT!!!
To solve this problem, I had to download Windows Installer Clean Up from Microsoft website, remove MSXML 6 and then re-run setup for either SQL Server 2005 Express SP2 or SP3, the installer ran successfully and the Database Service can be installed...SOLVED!!!
I also read that this problem also found at SQL Server 2008 Express, can anyone confirm this?