SessionHeader crmSessionHeader = new SessionHeader();

WebServiceSoapPort CRMService = new WebServiceSoapPortClient();

void GetAllRecordsInEntity()

        {

            string listofFields = "";// blank will return all the fields or you can set the comma separated column names;

            string whereClause = "";//" blank for no condition or set as "type='user'" for condition

            string entityName = "Users";// Define entity name (which is a database table) here 

            string orderBy = "";// set  order by with desired column

            queryrecordResponse objQueryRecordResponse = new queryrecordResponse();

            queryrecordRequest objQueryRecordRequest = new queryrecordRequest();

            objQueryRecordRequest.fieldlist = listofFields;

            objQueryRecordRequest.entityname = entityName;

            objQueryRecordRequest.queryString = whereClause;

            objQueryRecordRequest.orderby = orderBy;

            objQueryRecordRequest.SessionHeader = crmSessionHeader;            

            objQueryRecordResponse = CRMService.queryrecord(objQueryRecordRequest);

            queryrecordresult myQueryRecordResult = objQueryRecordResponse.result;            

            crmrecord[] myRecordList = myQueryRecordResult.records;            

            for (int i= 0; i< myRecordList.Length; i++)

            {

                recordfield[] myFieldList = myRecordList[i].records;

                for (int j= 0; j< myFieldList.Length; j++)

                {

                    recordfield myField = (recordfield)myFieldList[j];

                   //use myField.name for column name and  myField.value for value field

                }

            }

        }