Default [Q] Terminal Emulator cd root permission denied

Hi,
I am running on Cynogenmod M7,
I did not took a backup of my rom till now.
So today i backed up my rom and as the backup is occupying my phone internal memory i thought of copying to my laptop and delete from my phone.
But when i connected my phone to laptop i cannot find the backup.
Through emulator i tried accessing root folder. It throwed me permission denied error.

Please help me copy my backup rom from phone memeory
and also let me know why cannot i access the root folder.

Thanks in advance.