Also when do you turn the unit on?
ok, tried you method but I find that Updater never actually sees the Nuvi so I never get to press the OK button before if goes into calibration mode. I have the latest version of updater running on a Win 7 laptop. I've confirmed the USB ports work on the laptop and the Nuvi.
I have tried updater v2.8 and V2.7. Both are not able to see the Nuvi. Is there any chance that my Nuvi may have preboot mode disabled?