I just purchased a brand new 3790T device. Before ever turning it on I went to register the device on the Garmin web site. During the registration process it asked me to plug in the device. I did so and the device was properly registered.
On the next screen I saw that a software update was available for my device. I followed the instructions to update the software. After downloading the update (via myGarmin), it told me to unplug the device and let it restart. I did so (by using Windows "safely remove feature" then unplugging the device) but the device would not restart. I tried manually turning it back on, It simply gets to the "Loading Maps." screen and then restarts over and over. If I plug the device in to my computer Windows does not recognize it anymore.
So far I am not pleased at all. I haven't even used the device just to browse the interface and it's already dead. I emailed Support, but their response was utterly useless. They just told me to use the Web Updater program to apply the update again. Apparently they ignored me when I said that the device is no longer detected by Windows.
I have a feeling that they are only going to be able to resolve this by sending it in for repair. But I don't want to pay for a brand new, top of the line unit, just to have to immediately send it in for repair, and likely get a refurb unit back.
Unless some progress is made quickly, I will likely just return it to the store. I already tried to exchange it, but the retailer doesn't have any more of that model and can not get any more.