if you have a SD card, you can also try to flash "manualy".
- put your RUU... NBH at the root of the card,
- rename it trinimg.nbh,
- reinsert the card in the phone,
- enter in bootloader (power+cam+reset)
you will have a grey screen asking to push "power", do it and that's it.
if USB is well working, maybe you just need to reflash the hardspooler.