In-Place-Upgrade Windows Server 2008R2 to Windows Server 2012 Datacenter

Steps before upgrading:

  1. Make backups from all servers (physical and virtual);
  2. Reconfigure all hyper-v Virtual Machines (servers and/or clients) so that they didn’t start up automatically;
  3. Delete all snapshots from Virtual Machines (servers and/or clients) on the Hyper-v server;
  4. Delete unnecessary software, services and so on;
  5. Check eventviewer on critical events and solve them first before you go to the next step;
  6. Deïnstall any antivirus and Intel Pro software;
  7. Place DVD (or bootable USB-key  provided with the right OS) and open an elevated prompt;
  8. Run D:\support\adprep\adprep.exe /forestprep (in my case my DVD is drive D);
  9. Run D:\support\adprep\adprep.exe /domainprep (in my case my DVD is drive D);
  10. When there aren’t errors until this moment you can start the setup.exe in the root of the DVD;
  11. Follow the prompts and select Upgrade existing Windows installation. The setup will check your system if it’s compatible and report on any issues;
  12. Upgrade stage is provided. In my case this took more than 3 hours;
  13. Log in, start up all Virtual Machines and upgrade the HyperV Integration Services for each Virtual Machine
  14. Reboot the Virtual Machines after the process of installing Integration Services;

See also separate article about upgrading Integration Services on all the Virtual Machines. This article includes simple video’s.