Windows Libraries and Removable storage
I have been reading lots of comments verge forums, which recommends buying a 32 GB surface and expand the storage later using Memory Cards or USB drives.
I want to warn you guys. Adding folders from removable storage to Windows Library is not supported, it will give you above error. Which also means you will have limited (or no) access to these files from Metro Style apps like Music, Photos and Videos
Fortunately they are some workarounds but I'm not sure how well they work
Before you order any Windows 8 device with less storage, please do some binging to make sure they aren't any weird limitations wrt to removable storage.
(Also if you are already using the above workaround, let us know your experience)