Thread: Kenwood DNX 7240BT and LOADER LOADING problem.

I think that, when updating with CD, GUPDATE.GCD is copied to the internal flash drive of the Garmin device, and then GUPDATE.GCD is loaded by the Garmin firmware. Now it totally looks like something went wrong and GUPDATE.GCD is still there, making the Garmin firmware hang. Therefore, I think, you won't be able to update with GUPDATE.GCD until you cure the device.
To cure the device you need to enter the pre-boot mode (beware that it may be called in a different way, "service mode", etc) and proceed as GarminCure3 manual suggests and delete GUPDATE.GCD.
I don't know how to put your device into pre-boot mode, but maybe I'll ask one clever man tomorrow.

UPD:
roger1109 is right, firmware update is a lengthy process sometimes. So try waiting longer.