Exchange 2003 SP2 – Error code 0xC0070643

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

Okay I have a problem with my Exchange 2003 sp2

and

Exchange 2003 sp2 success on my home server!

and picture of the error here

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

Exchange 2003 SP2 Install Fails because of MSXML

But my error message was different to the above and Susan’s

I basically got

Product: Microsoft XML Parser — Product Installation failed

Well thanks.

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!