The OSName element contains the name of the operating system running on the domain controller.
<xs:element name="OSName" nillable="true" type="xs:string" />
The OSName element is populated from the computer!operatingSystem attribute on the Directory Server's computer object. The directory server's computer object is referenced by the server!serverReference attribute ([MS-ADTS] section 126.96.36.199.188.8.131.52) on the parent of the nTDSDSA object specified by the GetADDomainControllerRequest/NtdsSettingsDN (section 184.108.40.206.2.3) input parameter element. If the server!serverReference attribute is not present or cannot be read due to the client lacking access rights to read the attribute, the server returns the SOAP fault described in section 220.127.116.11.8.1. If the computer!operatingSystem attribute is not present or cannot be read due to the client lacking access rights to read the attribute, the server returns a null ActiveDirectoryDomainController/OSName element.