How do i get my USB ports to work again

My USB ports seem to have stopped working. When i plug anything into them now a message pops up saying something along the lines of "USB device is using to much power, please disconnect" and nothing works. I have tried every different USB connecting device and own and it says this nearly everytime, and when it doesn't it just doesnt find the connected device. I really need to get my USB ports working again so please if anyone knows how to fix this let me know!!!! Thanks