Thread: NEED HELP: nuvi 2455LMT can not connect to PC, after being formated

Hi All,
I did something really silly and now my 2455 can not connect to either Windows or MAC PCs

So this is what I did: after update the map, my unit always has to restart to reload the map and I was trying to clean the microSD to reinstall map. But I indeed format the garmin internal memory and all the files on the device are lost.
I was trying to connect the device to Windows 7 machine but the PC does not recognize it as USB drive, so I can not restore the device with my backup (my backup was indeed in MAC, but this is another story).
So now the unit starts but there is no map or what ever files needed to connect to PC.
1) I change the setting in MTP to make it "mass storage" but there is no luck of being recognized.
2) I tried to start the unit in preboot mode by holding power+upper left corner. The windows PC can recognize the GPS for very short time and even I keep pressing the left upper corner it will disappear from the device list in the device management of the Windows PC.

So now I need your help to get the unit to connect to the PC (or indeed recognized by the PC). Any help or comment will be appreciated greatly.

Thanks