As I am not very computer savvy, having a little difficulty updating checklists..I have a 3500 Non-S and a slave screen that is an "S" unit..For some reason, I have checklists on my SD cards that have file extensions "AFD" and One that is "TXT"..I tried to update them, but when I put them in the EFIS, it does not read the changes I made, and displays the old checklists. 1) Which file extension does the EFIS use...afd or txt? 2) Do I have to change both SD cards for the checklist to appear on each screen, or will the main EFIS drive the slave screen checklist? 3) Does someone have an update procedure for the checklists for windows 8.1, and if so could you post it? 4) If I were to delete the Checklist files, where do I download them again, and is this my best course of action?.......I apologize if this is a windows question, and not an EFIS-type question...since I have acquired Windows 8.1, everything has went to H-E double hockey sticks ...Any help appreciated..! Thanks!