|New flash drives always already have a formatted file system on them when you buy them. |
The drivers for recognizing it are generic drivers that are built into Windows.
Your flash drive may not be recognized properly if it's plugged into an external USB hub, or into a front port on a desktop case. It should be recognized fine when you plug it into a USB port that's physically built into the mboard - on the case on a laptop or netbook, or on the back of the computer on a desktop computer.
If you have an external hard drive plugged in, the same thing as in the following can apply - if the external drive and another USB device are plugged into ports sharing the same USB connection that can't supply 500 ma per port, both the external hard drive and the other device will probably not be detected properly.
For some desktop mboards you can have problems when an external hard drive is plugged into one of a pair of USB ports on the back of the case that are connected to the same USB controller, if there is another device plugged into the other USB port for the pair, because the pair can't actually supply 500 ma per port - they can only supply 500 ma in total. Usually those pairs of ports are one above the other, not beside each other. If you have two devices plugged into such a pair of ports, try plugging one of them in elsewhere on the back of the computer.
For MANY laptop and netbook mboards similar applies. The built in USB ports often cannot actually supply 500 ma per port - they supply 500 ma in total for two ports that are close to each other. In that case, the external drive should work fine if it's the ony thing plugged into the USB ports built into the laptop or netbook, or if you have more than two ports, the only thing plugged into two ports close to each other.