USB Duplicates Needed?

[Nehmo Sergheyev]

Win XP Home SP1

Under Control Panel > Administrative Tools > Computer Management >
Device Manager,
At the bottom right, under Universal Serial Bus controllers, I have
seven listings, each beside the trident-like USB symbol:

Standard Enhanced PCI to USB Host Controller
Standard OpenHCD USB Host Controller
Standard OpenHCD USB Host Controller
USB Printing Support
USB Root Hub
USB Root Hub
USB Root Hub

Are there supposed to be duplicate entries? For example, is there a need
for three USB Root Hub ? The properties of each differ on the number of
ports available. Under Properties:

One (oddly, not the labeled USB Printing Support) has, under the Power
tab,
USB printing support 4mA and
2 port(s) available 0mA

Another has, under the Power tab,
3 port(s) available 0mA

The last one has, under the Power tab
6 port(s) available 0mA

How can they do anything with 0 power available?

And what about the Standard OpenHCD USB Host Controller. Are there
supposed to be two of them?

Can somebody explain this section of Device Manager or provide a link
explaining it?

 

[Jim Berwick]

Are there supposed to be duplicate entries? For example, is there a need
for three USB Root Hub ? The properties of each differ on the number of

Yes, there are supposed to be multiple. One for each set of ports.