Addition of Exchange 2013 server to Exchange 2010 organization broke Exchange

This is somewhat of an emergency, since Exchange is down completely for us right now.

I just migrated from SBS2003 to Exchange 2010 on Windows 2012 over last weekend. Everything is now stable, and SBS2003 is shut down. Now I am attempting to migrate from Exchange 2010 to Exchange 2013.

The plan was this:

• Install Exchange 2013 on another server (Windows 2008R2)
• Wait until everything is replicated
• Remove the Exchange 2010  server from the organization
• Uninstall Exchange 2010
• Install Exchange 2013 on the Windows 2012 server
• Wait until everything is replicated
• Remove Exchange 2013 from the Windows 2008R2 server

But here is what actually happened:

• Installed all Exchange 2013 prerequisites on the Windows 2008R2 server
• Began Exchange 2013 server setup on the Windows 2008R2 server. Included both Mailbox & CAS roles
• At step 11 of 15 (not sure what that was, though), received this error message:
• Error: The following error was generated when "$error.Clear();
          netsh advfirewall firewall set rule group="windows management instrumentation (wmi)" new enable=yes   
          " was run: "The term 'netsh' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again.".

And setup halted. I ran the netsh command via the command prompt, and it correctly said something about four rules being created or updated (not sure of exact verbiage). Now, when I try to restart setup, it says it is in the middle and will try to complete but stays at 0%. But here is the most immediate issue:

• Now I cannot access e-mail from any workstations (says Exchange server is unavailable)
• Opening EMC on the Exchange 2010 server: I get as far as Microsoft Exchange -> Microsoft Exchange On-Premises and get this error:The attempt to connect to http://[Exchange 2010 FQDN]/PowerShell using "Kerberos authentication failed: Processing data from remote server [Exchange 2010 FQDN] failed with the following error message: Couldn't find Enterprise Organizaiton container. (Note that it refers to the local server as remote server)
• I get an event 7031 on the Exchange 2010 server: The Microsoft Exchange Service Host service terminated unexpectedly
• Opening the Exchange Management Shell on the Exchange 2010 server yields the same message regarding "Couldn't find the Enterprise Organization container..."

It also says, "Connecting to [Exchange 2013 server FQDN], then says connected to that server. Opening EMS on the Exchange 2013 server seems to connect correctly to the Exchange 2013 server, but there is no EM Console available there.

At this point, I am lost. I will continue to research this online but may have to call Microsoft soon, since we are entirely down at the moment. Any help is much appreciated!