Since the drive worked previously, this may not be your problem, but I just purchased a Toshiba netbook, plugged my USB DVD drive into it, and got a "Device not recognized" error. The drive worked fine with two other computers I have, so the problem was not the drive. After wasting a fair amount of time trying to figure out what was going on, I finally called Toshiba tech support. They said the computer was deliberately crippled (not their words) so that it would only recognize Toshiba-brand drives! What a raunchy way to try to force customers to purchase Toshiba products they don't need!