One must buy a powered USB hub (approx $20) at Best Buy, etc. It usually has a cord that plugs into your PC and on the other end is a "box" that you can plug 4 or more USB items into. What makes it powered is that it also has an external plug (for the wall) and that is where it it gets the power.
All USB items derive their power from the same plug as they send/recieve data from, therefore they (the USB items) are an added draw on your PC's power supply. Using a powered USB hub eliminates this extra power consumption from your PC's power supply and, in most instances, makes your computer and USB peripherals much happier.