If you windows domain does not have a (.local) on the end you will need to use this registry key to join it to the domain

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Netlogon\Parameters

1. Locate AllowSingleLabelDnsDomain. If the key AllowSingleLabelDnsDomain does not exist:

1. Edit, New, DWORD.
2. Write AllowSingleLabelDnsDomain as key name, and ENTER.
3. Double click AllowSingleLabelDnsDomain.
4. Set the Value to 1.
5. Exit regedit
6. Try to join the domain