The hand controller must be in boot mode for programming of firmware updates. To place the unit in boot mode the up and down switches must be held down at the same time when the hand controller is powered up. The LED will flash about 3 times per second when the hand controller is in boot mode. Alternatively, you can hold down these switches when you select the file to be uploaded and then release them once you see the LED begin to flash. Check here for the latest hand controller firmware and refer to here for how to use the MicroTouch application software to upload the firmware.
Note: Firmware updates to the motor controller do not need the hand controller to be placed into boot mode. The hand controller will command the motor controller to enter boot mode when you begin the firmware update to the motor controller.