If you get the error message “Windows cannot use this hardware device because it has been prepared for safe removal” you can easily fix it and get your USB device running again. Here’s how.
As pointed out, to fix this problem it is usually enough to unplug your USB device.
Let’s take a look:
USB hubs can also block their ports and disregard any new states if you plug in and plug out USB devices very quickly. As a rule of thumb wait 10 seconds between plugging in/out new devices.
Sometimes, you might corrupt a driver that way when you hit the reset button while the USB hub is accessing the drivers.
Remove your USB hub from the device manager and re-install the driver. That should fix your problems.