At this point, your data is backed up, you have verified compatibility with the new operating system, and you have read the release notes. It’s time to upgrade, so complete the following steps:
1. Log on to the server and insert the Windows Server 2012 media. The Install Windows page should automatically launch; otherwise, click Setup.exe.
2. Click Install Now to begin the upgrade process.
3. On the Get important updates for Windows Setup page, first select the I Want to Help Make Windows Install Better option. By doing this, you will participate in the Windows Installation Customer Experience Improvement Program that allows Microsoft to collect information about the hardware configuration, installation settings, and errors ...