Identifying the USB HCI Under Windows 2000/XP
To determine which USB HCI your system uses under Windows 2000 or Windows XP, right-click My Computer, choose Properties, display the Hardware page, and then click the Device Manager button to display the Device Manager. Double-click the Universal Serial Bus controllers item to expand it, as shown in Figure 24-9.

Figure 24-9. Windows XP Device Manager showing that this system uses two Intel 82801BA/BAM UHCIs
In this case, as is common on recent systems, the motherboard includes two distinct HCIs. These operate completely independently, and each HCI has a separate root hub associated with it. This doubles the number of root hub ports available, some of which may appear at the front of the case and some of which connect directly to the traditional location on the rear ATX I/O panel. Note that the secondary root hub ports often appear as a set of header pins on the motherboard, which may be extended to the front or the rear of the case, as necessary.