Theoretically, 127 USB devices can be run off of one USB port on the computer. There are, however, several reasons why this is not normally done. First, you would need 127 devices that could attach to one-another in a daisy-chain fashion. Some of these devices are available, but there are not many.
In fact, some keyboards that have USB ports for a mouse are the only “daisy-chain” products that are commonplace today. The other problem you would have with 127 devices is that you would need to have some supplemental power.
Because of these two limitations, hubs have become the most convenient way to add more USB ports and devices to your computer. When I needed to add more USB devices to my computer, I chose the Belkin USB 2 Hi-Speed 4-Port Hub. This is a compact rectangular device (5 ½" x 3 1/4" x 1") that can rest on top of your computer or on your desktop. You use the included cable to hook the hub to a USB port on your computer. Then plug the included power cable into the hub and into the wall. That’s all there is to it. You now have 4 extra USB ports that have additional power, ready to hook up all your USB devices. My windows XP machine found the hub immediately and automatically installed the necessary software. This Belkin device worked like a charm. Total installation time was less than 5 minutes.
This USB hub is a high-speed USB 2.0 hub. Provided you hook the hub up to a USB 2 port on your computer, any USB 2 device you hook up to the hub will work much faster than if you were using a USB 1.1 device. USB 2 is backwardly compatible with USB 1.1, so you can also use older USB devices with this hub. They will, however, work only at the slower USB 1.1 speed. The hub can be used to daisy-chain another hub if you need more USB ports in the future. The hub also has LED lights on the front that will light to signify the status of the port.
The Belkin USB2 4-port hub is compatible with Windows 98, second edition as well as Windows 2000, Me, and XP. Since it is backwardly compatible, you can purchase a USB 2.0 high-speed hub like this one even if your computer has only USB 1.1 ports. The hub will still be useable when you get a new computer with USB 2 ports.