I'm migrating from Exchange 2003 to 2013 using Exchange 2010 as an intermediate server.  I have already moved all the mailboxes and really want to decommission the 2003 server so I can get started installing 2013.

I want to make sure that all public system folders have been replicated.  The organization doesn't use public folders, also no Outlook 2003 clients, but I read that all replicas must be moved and then removed before the server is decommissioned.  I'm just not sure if all replicas were put into place.  I am going to paste the out put of the Get-PublicFolder -recurse \non_ipm_subtree |fl name, replicas command.  There are some folders that do not have replicas and I'm not sure if that is normal or not.

Name     : NON_IPM_SUBTREE
Replicas : {}

Name     : EFORMS REGISTRY
Replicas : {}

Name     : Events Root
Replicas : {Public Folder Database 0215671898}

Name     : OFFLINE ADDRESS BOOK
Replicas : {}

Name     : /o=ABC/cn=addrlists/cn=oabs/cn=Default Offline Address List
Replicas : {Public Folder Database 0215671898}

Name     : OAB Version 2
Replicas : {Public Folder Database 0215671898}

Name     : OAB Version 3a
Replicas : {Public Folder Database 0215671898}

Name     : OAB Version 4
Replicas : {Public Folder Database 0215671898}

Name     : EX:/o=ABC/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)
Replicas : {Public Folder Database 0215671898}

Name     : EX:/o=ABC/ou=first administrative group
Replicas : {Public Folder Database 0215671898}

Name     : OWAScratchPad{0E2CB511-8CBA-401D-97E5-0DBC4CB924EE}
Replicas : {Public Folder Database 0215671898}

Name     : SCHEDULE+ FREE BUSY
Replicas : {}

Name     : EX:/o=ABC/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)
Replicas : {Public Folder Database 0215671898}

Name     : EX:/O=ABC/OU=EXTERNAL (FYDIBOHF25SPDLT)
Replicas : {Public Folder Database 0215671898}

Name     : EX:/o=ABC/ou=first administrative group
Replicas : {Public Folder Database 0215671898}

Name     : schema-root
Replicas : {Public Folder Database 0215671898}

Name     : Default
Replicas : {Public Folder Database 0215671898}

Name     : microsoft
Replicas : {Public Folder Database 0215671898}

Name     : exchangeV1
Replicas : {Public Folder Database 0215671898}

Name     : StoreEvents{0E2CB511-8CBA-401D-97E5-0DBC4CB924EE}
Replicas : {Public Folder Database 0215671898}

Name     : globalevents
Replicas : {Public Folder Database 0215671898}

Name     : internal
Replicas : {Public Folder Database 0215671898}

It's normal that those don't have replicas because they're not really folders, they're just directory containers.

Thanks Ed.  Ok good.  So I should be safe to remove replicas and decommission server?

It doesn't look like you have any replicas remaining on the Exchange 2003 server.  But the Exchange 2003 server might not agree.  Sometimes the replicas are sticky.  Post back if you have problems removing the public folder database.

I was able to successfully decommission the Exchange 2003 server.  But when I did, the next time I rebooted the Exchange 2010 server I could not get any Exchange services to start.  After hours of anxiously searching for an answer, I found a forum post about adding the exchange server computer account to the domain admins group.  I was then able to restore service on the 2010 server.

Question is why did I have to do that?  It doesn't seem normal.

You shouldn't have to do that.

Right.  This is the article that helped me.

http://blogs.msdn.com/b/keithmg/archive/2009/01/06/exchange-topology-discovery-failed-error-0x80040a02-dsc-e-no-suitable-cdc.aspx

Still would like to fix the root of the problem.  Perhaps I should create another forum post.

I would definitely recommend that.