Specifies whether the DNS client should convert internationalized domain names (IDNs) to the Nameprep form, a canonical Unicode representation of the string.
If this policy setting is enabled, IDNs are converted to the Nameprep form.
If this policy setting is disabled, or if this policy setting is not configured, IDNs are not converted to the Nameprep form.
At least Windows Server 2012, Windows 8 or Windows RT
Not Configured - No registry values are specified.
Disabled - Any values that would be created by the policy in the registry are deleted.
Enabled - Adding, modifying or delete values in the registry.
User Interface can be found in the Group Policy.
Please navigate to Computer Configuration - Policies - Administrative Templates - Network - DNS Client folder.