Here is 12 simple steps to Join Windows 8 to Windows 2012 Server Domain.
1. Log into the Windows 8 client computer you want to join to the domain.
2. Make sure you have set static IP and you have the DNS IP address pointing to the server.
3. Type domain in the metro UI. Open up the Settings Search and Join a Domain.
4. Select Change, Select the Domain radio button, and type in the domain name.
5. For this tutorial, Im using AvoidErrors.home and Press OK.
6. You will be prompted to enter Domain Admin Credentials to join computers to the domain. I will be using my Domain Admin account.
7. If there were no problems with your credentials, follow the prompts to reboot.
8. Once rebooted, Log into the local computer.
9. You can see this by looking at the current username CLIENT-PCLOCAL-USER.
10. Press the left arrow to switch users. Select Other User.
11. You need to log in using Server2012Local Username
12. At this point, you are on the domain.