Unable to uninstall the Nortan 360 Backup file on windows

Hello, I uninstalled Norton Security awhile ago from my desktop because the backup file was taking up almost 70gb on my disk, it automatically saved to my C: drive.
Once I uninstalled, I continued to get messages that my disk is completely out of space, I went through windows explorer, found the N360_Backup file that is 73gigs...when i tried to delete it I got an error message saying "Cannot delete backup.@db:  Access is denied.  Make sure the disk is not full or write-protected and that the file is not in use"  I already tried to unprotect it by unchecking the "read Only" box in the folder properties, however it won't allow me to change it...what can I do to get rid of this space eating folder?