Problem in deleting extra folders in a Toshiba computer on Vista

Our Toshiba has an OS Vista. It has document files and all files have green folders in the Library. Under the documents, there is another Manila folder named Documents. Under the green folder named Documents, if we try to delete the extra folders, all the other folders would be deleted too. Why does this thing happen? We have also a Sony and a Dell that has OS Windows 7. We do not experience the same problem with these computers. Why is it that the Toshiba unit is different, that when you delete the extra folder that has the same files, nothing would be retained and instead, everything would be deleted? Please give me some explanation and solution to this problem. Thank you.
