Hi, I had the same problem (on windows 7)
In the device manager, I pointed windows to the directory of flip 3.4.7, there he found the driver.
After the driver installed, I followed the upgrade instructions from Arduino; I ran:
batchisp.exe -device AT32UC3A1256 -hardware usb -operation erase f memory flash blankcheck loadbuffer “C:/Program Files (x86)/Arduino/hardware/arduino/firmwares/wifishield/binary/wifi_dnld.elf” program verify start reset 0
which worked, and then
batchisp.exe -device AT32UC3A1256 -hardware usb -operation erase f memory flash blankcheck loadbuffer “C:/Program Files (x86)/Arduino/hardware/arduino/firmwares/wifishield/binary/wifiHD.elf” program verify start reset 0
which failed again. I had to reset the device to complete this last step.
Now the command WiFi.firmwareVersion() gives 1.1.0 as the version number.
However I still have the feeling that the firmware upgrade didn’t complete correctly because I still can’t get a response from the web server in the example WifiWebServer (in Arduino 1.0.6)
Does anybody have an idea why I need to reset the device between the two steps in the firmware upgrade? And, if this might be a problem?