Here is a list of a few steps to join your computer to an Active Directory domain:

1. Confirm the Domain Name. Find out what the domain name is, then ensure that the computer is connected to the network that you use to sign into the domain.
2. Install the Active Directory Domain Service (AD DS). Install the AD DS on the computer you are attempting to join in order to connect and sync it with the domain.
3. Join the Domain. Enter the domain name in the Join a Domain dialog box, then choose the default password and click join.
4. Log into the Domain. Log in to the computer using your domain credentials, such as your username and password.
5. Verify the Computer's Membership in the Domain. Open the System Properties and check if the computer domain name matches with the shown information.