Dear All, I am having One forest with a primary domain controller and in same forest there is one child domain controller server01.abc.com server02.xyz.abc.com I have configured total 7 number of additional servers for this server02.xyz.abc.com at different location. my all servers are running on windows server 2003 enterprise edition 32 bit OS. we have more than 10,000 PCs in the network. my primary domain controller is also having one additional domain controller. I have configure ISA Server 2006 enterprise storage configuration of array with server01.abc.com I want to join one child DC's additional server into this storage array of ISA Server 2006. when I am going to join into existing storage configuration array it showing me an error as per below An attempt to use windows authentication to authenticate the request sent to the configuration storage server computer failed. Refer to getting started guide for help on setting up windows authentication. Please do help needful.. Bhavyang R Patwari https://www.mcpvirtualbusinesscard.com/vbcserver/bhavyangraj/profile