I am upgrading Adfs 2.0 server 2008 to Adfs 3.0 server 2012 r2. In server 2008 Adfs service is running under network service, while configuring 3.0 on 2012 i don't get that option. To import the config from adfs 2.0 to 3.0 you must use same user/ service
account that you are using for 2.0.
Please advise either how to change the service account on 2.0 so I could export the config with new account or how to add NT Authority\ network service account to configure Adfs 3.0 on 2012 server.