http://bugs.winehq.org/show_bug.cgi?id=15533
--- Comment #10 from Reece Dunn msclrhd@gmail.com 2009-01-06 11:30:58 --- MSI error 1603 is a generic "something went wrong" error.
WiX is an open source MSI installer creator by Microsoft, available on sourceforge. Using the power of Google, I suspect that this functionality is mentioned in http://www.joyofsetup.com/2008/05/17/new-wix-feature-firewall-extension/.
It looks like iTunes is trying to query the Windows Firewall services and is failing because Wine does not implement this interface yet (bug 15563, bug 12876 and others).
Do you know if the logs mention trying to CoCreate {304ce942-6e39-40d8-943a-b913c40c9cd4} (CSLID_NetFwMgr)? If it does, then this seems the most likely scenario.