sometimes I say important things in class

Most keyboards and USB hubs operate from power supplied by the USB ports to which they are connected; this does not leave enough power for some brands of flash drive to operate properly. To avoid this, always connect the flash drive to a USB port that is DIRECTLY ON the computer. This means you should not use ones on the monitor (unless the monitor is also the computer), keyboard, or other peripherals. This should allow it to power up properly.