Hi, you can do it by using a namespace. Here is a not so elegant way of getting the value out:

DECLARE @xml XML = '<?xml version="1.0" encoding="utf-8"?>

<DataSet xmlns="http://tempuri.org/">

<xs:schema id="NewDataSet" xmlns="" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">

<xs:element name="NewDataSet" msdata:IsDataSet="true" msdata:UseCurrentLocale="true">

<xs:complexType>

<xs:choice minOccurs="0" maxOccurs="unbounded">

<xs:element name="Table">

<xs:complexType>

<xs:sequence>

<xs:element name="KeyID" type="xs:string" minOccurs="0" />

<xs:element name="LicenseAcquisitionUrl" type="xs:string" minOccurs="0" />

<xs:element name="CHECKSUM" type="xs:string" minOccurs="0" />

<xs:element name="ContentID" type="xs:string" minOccurs="0" />

</xs:sequence>

</xs:complexType>

</xs:element>

</xs:choice>

</xs:complexType>

</xs:element>

</xs:schema>

<diffgr:diffgram xmlns:msdata="urn:schemas-microsoft-com:xml-msdata" xmlns:diffgr="urn:schemas-microsoft-com:xml-diffgram-v1">

<NewDataSet xmlns="">

<Table diffgr:id="Table1" msdata:rowOrder="0">

<KeyID>ABA38156-D357-4C2A-933A-838604EE4F83</KeyID>

<LicenseAcquisitionUrl>http://ready.steady.com/preauth.aspx?pX=0DF3E4</LicenseAcquisitionUrl&gt;

<CHECKSUM>0A38b6k3kiQ=</CHECKSUM>

<ContentID>zqFuE60mxIQEWEzYyxoMkw==</ContentID>

</Table>

</NewDataSet>

</diffgr:diffgram>

</DataSet>

'

;

WITH XMLNAMESPACES (DEFAULT 'http://tempuri.org/')

SELECT @xml.value('(//DataSet/*:diffgram/*:NewDataSet/*:Table/*:KeyID/text())[1]', 'UNIQUEIDENTIFIER')

, @xml.value('(//DataSet/*:diffgram/*:NewDataSet/*:Table/*:ContentID/text())[1]', 'VARCHAR(24)')