We have an old AD 2003 Forest that we want to upgrade to 2012. It is a relatively small environment but vital none the less. I know that the 2012 upgrade process is straightforward and the Adprep will automatically run during a Role-based or feature-based installation. However, as I understand the 'adprep /domainprep /gpprep' does not run since it is not part of the automated process.
I don't think gpprep was ever run in this environment in the past so can I run gpprep after I have completed the domain upgrade process from 2003 to 2012? Are there any ramifications if I do so?