I ran the install and the screen showed a 4 stage diagram of what needed to be done and it started working on the GPS.
Within a few minutes it needed to restart the gps so I followed the instructions and unplugged, waited 5 secs, and replugged in the device.
It thought about it for a while - with no indication of what was going on and then eventually restarted and I had to press "I agree" on the GPS unit to indicate I wouldn't touch it while moving.
At this point I had two dialogs showing - the main dailog said it was connected to the nuvi GPS and was initialising and that "it might take a minute". And also a pop-up dialog indicating it was searching for the device. I got the feeling that these two dialogs were causing each other to hang since nothing changed for over five minutes - just two whirly icons indicating working.
So I hit the close x (top tight) on the searching dialog and was asked if I wanted to leave the page - I said no and it went back to showing the same again. Afer a few minutes I tried the cancel button and was prompted if I wanted to leave the current update page so I said yes and the dialog showed the startup screen.
I clicked on the nuvi and this time it said only map updates were needed, so I went ahead and clicked install - and right now it is showing that it is downloading files. So I'm thinking it did hang looking for the nuvi gps and if i'd left it it would still be sitting there now.
So - in summary - Garmin software used to be utter shite, and now it's just a bit shite. My advice is that if it shows 2 disagreeing dialogs during update, try cancelling and going again. Express obviously can't cope with software and map updates at the same time!
Garmin GPS is a good bit of kit... updating it has always been a bit infuriating.