Okay, first, forget about WebUpdater. I'm not using it, so I can't give an advice if it fails. Use updater.exe and pre-boot mode for flashing firmwares.

Quote Originally Posted by Donovan2123 View Post
I have done this but when I load original firmware using garminCure.exe my car device becomes unrecognisable by computerso ccan'tdo web
uupdate and it still hangs on garmin logo.
As far as I can understand your message:
1) When CURE firmware is flashed, the device is seen as a flash drive by the PC and WebUpdater detects it and successfully downloads firmware update.
2) When ORIGINAL firmware is flashed in pre-boot mode, the device is not seen as a flash drive anymore and it hangs on Garmin logo.
Do I understand you correctly?
If so then it means that you haven't cured your device. Try formatting it as suggested here: [Only registered and activated users can see links. ]. Also backup the files on your device but don't restore them immediately after formatting, try booting the device with empty flash drive. One of the files could be causing the problems.