My computer has USB1 on the M/board. I wanted to expand to USB2 speed and installed a PCI 4+1 USB port card and Windows XP installed it.
The drivers all looked OK but would not read an external HDD or work a new scanner. By trial and error I disabled all the USB1 original ports, then switched off the Bios support for the M/board USB1 and not until I disabled 'standard Enhanced PCI - USB open host controller' on the device manager, did I get my external gear to work.
Now I find this is working at USB1 speeds. (by measurement and by XP advice bubble) I have gone round in circles to find I am back to where I started! How do I get the proper driver/system to recognise the attached equipment and work at the higher speed? (The gear works fine)