boot problem

My BBGW seems to have the eMMC corrupted. The power and WLAN LEDs stay on, but the user leds isn’t blinking. In the device manager it’s possible to see that the beaglebone is beeing reconized, but it don’t start as USB card in “My Computer”. I tryed to boot by SD card and tryed to flash a new image to the eMMC, but nothing works. Is there something I can do?