Xcopy & Secure Folders

I recently installed a RAID 1 Thecus NAS Device on a Network
Initally all the Folders were open but the Customer requested 3 Users have secure Folders which I configured n oproblem
On an evening as an extra backup i use Xcopy to copy the Folders onto another device, this works fine for the open folders but I get "Invalid Drive Spec" when I try to Xcopy the Secure folders across

Is this because only the User has permission to access the said folders

Is there another way round this

Thanks for all responses

grant the user that xcopy runs as permissions on the folders. If the woman doesn't accept this make sure she's aware that they won't be getting backed up.