Good solution possibility David

However, I think that it may be possible that the USB Power was overloaded, not having enough left over for the drive, which would also explain why turning devices off helped to solve the issue. Once they were turned off more power was available at the port the drive was plugged into..meaning it wasn't necessarily that your computer wasn't seeing that many devices, but that the power wasn't there for the device to properly boot.

Still another great idea to try.

I do not work here, but the benefits are still awesome
Make your sound your own!