I teach online courses in Blackboard. For the assignments, the student have to open a .pdf file, fill in their answers, save the .pdf and attach the .pdf file to the assignment. 95% of the students have no problem doing this. The other 5% keep sending me .lnk files. I tell them to redo making sure they save as .pdf. I even made them a tutorial with step-by-step instructions. They say that even though they save to the file in their My Documents folder as a .pdf, it changes to a .lnk.
Anyone have any ideas how I can guide them to get this right?