Make sure that you are looking in the correct location.
Do you see "USB bus controllers"? If yes, click the little + to devlop it.
If your Windows version is NOT in English, the actual name displayed is probably different. In Frensh, it's "Contrôleurs de bus USB"
In turn, double click each item you can see.
Sellect the "Driver" tab.
If you see a button labeled "Activate", click it. That device was deactivated, making it unusable.
Go to the "Power management" tab if there is one. Here, you may want to uncheck the option to turn the device OFF to save power. Anyway, an USB port realy don't use that much power.
Repeat this for every device present.
Any device that is deactiveted AND set to be turned OFF to save power is a source of problem as it tends to totaly disapears from many places.
Electro
October 2013