To back up a minute, how did you determine that it's treating them as 1.1 and not 2.0? Is that what Windows is telling you when you plug a 2.0 device in, or is it by another indication? If you see the word "Enhanced" in Device Manager's description, that does mean 2.0 as well.
Aside from a driver issue, if the cables that connect a case's front USB ports to the motherboard are not USB 2.0-compliant, then that could cause it to downshift to 1.1 mode too. If you're using the cables and outlets that came with the motherboard, or if your case's cabling is definitely USB 2.0-compliant, then you can disregard that possibility.
So if it's truly a driver issue, next thing you can do is go to Device Manager and simply do an Uninstall of the USB stuff, then reboot and let Windows re-discover it, and see if it's now Enhanced or 2.0 in Device Manager afterwards.