Create in it a directory named Garmin, restart it and see if you get garmindevice.xml in it (or garmindevice.temp to rename to garmindevice.xml)
If you get garmindevice.xml run Garmin Webupdater.

PS. If you get Garmin logo it can go to preboot mode and use Updater.exe. You have to retry
Edit:
PS.#2 Updater.exe is not Garmin Webupdater. You must read better step by step guide and my post above.