The Exchange migration I did this week involved moving the current Exchange setup onto new hardware (we talked about Exchange 2007 / Windows Server 2008 but the client was going with the “if it’s not broke don’t fix it” viewpoint combined with a tight budget!)
After I’d installed Exchange on the new hardware one of the first things I did was install Service Pack 2
I got the following error
Setup failed while installing sub-component Exchange ActiveSync with error code 0xC0070643 (please consult the installation logs for a detailed description). You may cancel the installation or try the failed setup again.
This rang a bell and sure enough a quick look on Susan’s blog found the following posts which pointed to a registry key for the XML Parser in place that needed to be deleted
Thing is this was a brand new installation. So there wasn’t anything else that had installed the XML Parser so no registry key to delete!
After a bit more digging I found this post by Colin Bowern
But my error message was different to the above and Susan’s
I basically got
Product: Microsoft XML Parser — Product Installation failed
So I located the msxml3.msi file in the Exchsrvr\bin directory and tried to run it manually. I simply got the same error
Obviously the setup was trying to install using that MSI and failing so I borrowed the trick Colin mentions in his post
This worked for me so I’m making a note here in case I need it again!