It will load the cure correctly in pre-boot, and the screen shows the loading function, and G7towin shows a change in firmware, but it will not get past the Garmin logo on reboot. So there is some other file corruption. RM USBprep does not see the drive.

AFter booting - it hangs at the Garmin logo and about every 90-120 seconds, it goes to a white screen and then reboots to the logo. So I am at a loss. It will not get to the point in the post you suggested above be recognized by the PC.