Mefranky
Okay, then remove X:/Garmin/GUPDATE.GCD (where X: is the flash drive letter of your device). After that you would need to flash ORIGINAL firmware, as CURE firmwares made by GarminCure3 are not bootable. Do it as follows:

Open the firmware file with GarminCure3 and make sure ORIGINAL is selected.
[Only registered and activated users can see links. ]

Then press "Make firmware".
[Only registered and activated users can see links. ]

Then press "Updater.exe".
[Only registered and activated users can see links. ]

Updater.exe program window should appear. Make sure "USB device is selected.
[Only registered and activated users can see links. ]

Then put your device into pre-boot mode and connect it to the PC. Then updater.exe should detect it. Press "OK" and firmware update process will start.
[Only registered and activated users can see links. ]

After that your device should be working normally. If it still doesn't work then we will try something else.