I recieved the free update yesterday and was unsuccessful on repeated tries with my computer to update the gps. It would take all the info and then flash an error screen without explaining what the problem might be.
I called Garmin support early this morning and found out that my only need was for high speed internet, along with the stated computer requirements. I dont have high speed internet at home, no need, til now. I later found a computer with all the needed features and the update took 40 minutes. I drove home with the new updated NT 2008 gps on my dash. The entire 1.9 miles. I will be leaving for a 4k mile trip mid week.
Apparently the gps flashes a checksum back to the mothership at each turn of the map in order to keep the whole operation propietary. Clever but inconvenient for me-gotter done nevertheless. Had the operation of updating been more convenient ie on dialup, I wouldnt have had a scowl of dissappointment nearly all day.
The update dvd erases the maps on the unit's harddrive first, then , without
being able to complete the update, the gps is as useless as a hockey puck in summer. There is no way to preserve or return to the previous software.