You may receive an error like the following:
MSP Error: 29513 SQL Server Setup Failed to compile the Managed Object Format (MOF) file C:\Program Files\Microsoft SQL Server\90\Shared\sqlmgmproviderxpsp2up.mof
The file may exist as sqlmgmprovider.mof, which is a former version created for a former version of the OS (example: you had Windows 2000 Server installed and then upgraded to Windows Server 2003).
The workaround suggested by Microsoft did not work for me. So I simply renamed the file sqlmgmprovider.mof to sqlmgmproviderxpsp2up.mof which let me install the SP2 of Integration Services.
A variety of issues, just look at the discussion with 136 replies regarding MSI installer files issues. For the relatively benign
Error 29528. The setup has encountered an unexpected error while Setting Internal Properties.
this easy fix did it for me: http://support.microsoft.com/kb/925976
Just throw away the quoted keys and they will be re-created by the subsequent installation of the service pack, which will hopefully be successful.
It seems SP 2 was rushed out the door, as this insider post confirms, so it might be good advice to wait for SP 3.
Ezequiel: Thank you! Your renaming solution did the trick with our SP4 installation problems.