Do you still have cure fw on board? You haven't mentioned if you loaded original fw again. I'd do that if you haven't already, then either hard reset it or clear nonvol and also check you have latest Garmin USB Drivers loaded to PC. If it's still not recognised and/or you can't allocate a drive letter in Disk Management, load cure again and attempt to reformat it with RMPrepUSB. The only file you'll then need on the device is an empty Garmin folder in the root, probably not even that for it to boot fully. I think 25x5 will boot empty anyway from my [uncertain] memory. You can replace most everything with WebUpdater and MapUpdater, or use GarminExpress for both software and maps. You'll need to load a basemap and maybe some other stuff from your backup, but be wary as one of those files may be the villain.