Garmin nuvi 350 GPS Receiver "260 keeps" Questions

I have the garmin nuvi 260, and downloaded the update to my computer in June, then to my gps from there. Now I have a huge file on my computer. Do I need to keep it there? I bought the lifetime ...

260. It keeps telling me I need to update my maps, but I do not have a USB port for this unit. How do I go about proceeding with updates? the USB port is the same as the power feed port, if not have u

Garmin Unit 260 lrg My unit is functionning properly - I went to the Garmin website to download for free upgrade. Upon installation, the system requests a PRODUCT KEY. I searched everywhere for it....