what rickie is telling you is correct and the right thing to do.who does things right?not me. im always cuttng corners not reading instructions....... the unit is used right ,there is no warranty, no need to register.the site that we have recommended has all the updates for your unit and any questions you have can be answered there. the reason that i recommended the cheap sandisk card instead of the ex stream card is because ive used both .theres not that much difference in right speed for the price difference unless you catch a sale going on.i wouldnt waste money on buying two cards either .if you need change the update,just remove whats on the card then go back to web sight and get different update.when you done remove the update from your sd card or you can leave it on there,you can leave more than one version on the card,it doesnt matter ive done.if you leave update on card all that will happen is at bootup a message will appear saying you already have version installed. use that same card for waypoints,snapshots,video......... if you need more you could alway buy extra sd cards. ive never needed more than the 1 gig for a days fishing. when your card gets full, you can save all info on the card to viewed later on your computer.put the clean card back and go again.like i said rickie telling you the right way im just giving you a cheaper alternative route to take with the and result being the same thing. if you dont do anything else i think that you should at least register at Humminbird Side Imaging Forums .its free and you will learn a lot there.good luck