After almost 2 weeks trying, i managed to install both Windows 7 and Windows 8.1 Finally !! Without the need of unattend.xml file !! SCP was also able to assign the password for "Administrator" user as well as the Network IP Address...

unattend was not important for win 7/8 as they are non production servers, and trying to add unattend.xml gave me extra unnecessary headache so i decided to try without it and it worked like charm !! if you are using win 7/8 however you need to enable the built in administrator account and disable other unnecessary local accounts as scp will only then be able to assign IP for the Administrator account !...

Thank you,