Thanks, once I got the other computer to see the device (can't flash a device that doesn't show up in device manager), I was able to reflash it.

Then I took it back to my laptop, and it still wasn't seeing it. So I switched USB cables, and it did. Then I switched back to the original USB cable, and it worked with that cable again. (Note that I had hooked up a M5StickC via the original USB cable, and it is working fine with that cable now, so the cable isn't bad).

Gotta love Microsoft Windows sometimes.