How were you powering the board? With the Galileo, it is recommended to always connect the power supply before the USB port cable. If the board is left powered just with USB it might get damaged.
Is your board still recognized by the device manager? If it is then you can try accessing Putty and try to recover it using the recovery method Intel® Galileo Boards and Kits — Recovery Mode .
It was powered from the AC adapter. I was using telnet for access via Ethernet. The USB cable wasn't connected at all.
No, it's not recognized. This morning when I plugged it in, one of the LEDs flashed on briefly (much less than a second), then nothing.