What's the deal with the USB Ports?

I am still extremely puzzling about why in the world the USB ports (5 of them) at the back of my computer stopped functioning. The ironic part? The ports on a USB hub that directly attached to one of the port at the back WORKED. So now instead of using any of those direct ports at the back of the computer, I have to use the ports extended from the USB ports. I even have to add USB hub on the top of a USB hub. I guess eventaully I need to spend some time to rewire all the USB devices to figure out what the heck is going on.