For security purposes I set up some type of virtual disk in my documents folder - I can't remember what it's called and I can't spot its name in the index of my Mac Essentials book. I just click on its icon to mount this virtual disk, then I have to go to Macbook via Finder to click on it to open it. In my documents folder it has a little sheet of paper w/ a hard drive pic on it as its icon and in Macbook it has a little hard drive icon. I have open and read/write privileges w/out using a password, but it's not accessible to other user accounts.
I tried to add a new folder today and there's no New Folder Option from the drop down menu via that little grey button w/ the cogwheel on it. The New Folder Option from the File drop down menu in Finder is greyed out. There is plenty of capacity left via Get Info.