Windows 7 Forums
Welcome to Windows 7 Forums. Our forum is dedicated to helping you find support and solutions for any problems regarding your Windows 7 PC be it Dell, HP, Acer, Asus or a custom build. We also provide an extensive Windows 7 tutorial section that covers a wide range of tips and tricks.

Windows 7: USB controller and hub weirdness, which driver handles which port

14 Feb 2012   #1

Windows 7 Ultimate 32-bit, 64-bit
USB controller and hub weirdness, which driver handles which port

I didn't know whether to put this in General, or Hardware, or Drivers, or what. But here goes.

This particular system has Windows 7 Ultimate 32-bit, with an Abit KN9 Ultra motherboard. I was having some USB issues (a particular external USB drive wouldn't work when plugged into the front USB ports) so I started some investigating.

I thought that the built-in USB ports on a motherboard (on the back of the computer) are connected to a particular USB hub which is handled by a specific USB driver. But that doesn't appear to be true!

This is strange: When my Microsoft optical mouse is plugged into a particular port on the back of the computer, Device Manager says this when viewed by connection:
Standard OpenHCD USB Host Controller
USB Root Hub
Microsoft Hardware USB Mouse
Microsoft USB Comfort Optical Mouse 1000
(Those are indented to indicate "child" devices)

That would indicate that this particular USB port is a low-speed USB port, which worried me. BUT, if I unplug the mouse, and plug the printer in to the port that the mouse was connected to, I see this in Device Manager:
Standard Enhanced PCI to USB Controller
USB Composite Device
Canon MF4320-4350
(Those are indented too)

...which means that the SAME physical USB port is now a USB 2.0 port (Enhanced).

How can the same USB port be driven by Standard OpenHCD USB Host Controller driver one minute, and Standard Enhanced PCI to USB Host Controller the next minute? If that's how things are done these days, that's fine, but I never knew this. And the behavior was clouding my investigations -- I was convinced that the USB headers on the motherboard were not USB 2.0 (even though the documentation says they are, and Windows never complains that devices "could" perform faster if plugged into a high-speed port, etc.).

I thought that a physical USB port was connected to an on-motherboard set of circuitry that is handled by ONE driver, but apparently Windows moves drivers around when it wants to. Is this commonly known? Am I crazy? Does this happen to other people?



My System SpecsSystem Spec
16 Feb 2012   #2

Windows 10 Education 64 bit

I would say, if the device is not USB 2 capable it uses the Standard driver and if it is USB 2 it uses the Enhanced driver. My HP DVD-RW USB drive shows up under Standard Enhanced PCI to USB Host Controller but my Logitech keyboard and mouse show up under Standard OpenHCD USB Host Controller.
My System SpecsSystem Spec
16 Feb 2012   #3

Windows 7 Ultimate 32-bit, 64-bit

That's what it appears, but I didn't know that a USB port would or could MOVE AROUND to different USB controllers.

It makes it hard to figure out "which USB controller is handling which USB port?".

Since it seems to depend on what device you have plugged in to that port, the answer is indeterminate.

I didn't know that Windows worked this way.
My System SpecsSystem Spec

16 Feb 2012   #4

Windows 10 Education 64 bit

The physical port isn't moving around as you put it. The mode or driver used may change and thus its description may change in device manager, but the port doesn't move. Thats the way it looks to me anyway.
My System SpecsSystem Spec
16 Feb 2012   #5

Windows 7 Ultimate 32-bit, 64-bit

Well I know the port isn't moving around physically! At least not that I have noticed.

But I didn't know that the "controller" for a port could change (or at least the driver that runs the controller) depending on what you plugged into the port. Very weird.
My System SpecsSystem Spec
16 Feb 2012   #6

Windows 7 Professional SP1 - x64 [Non-UEFI Boot]

You could check that here: USB Selective Suspend - Turn On or Off

and then here: USB Driver - General Fix for Problems

Hope this help...! And welcome to SevenForums!
My System SpecsSystem Spec
16 Feb 2012   #7

win 7 X64 Ultimate SP1

When you plug into a USB port the OS analyzes it and loads the appropriate driver for that device. (if a driver is available) Does this help understanding it.
My System SpecsSystem Spec
16 Feb 2012   #8

Windows 7 Ultimate 32-bit, 64-bit

I know how drivers work, but I never knew that Windows would move USB devices to a different controller. I thought a specific driver handled a specific set of circuits on the motherboard (or add-in card).

I know there is a parent/child relationship between USB controllers, hubs, and devices. Windows can apparently move USB devices from one controller and hub to another. I presume the USB hub is more of a virtual concept than an actual device, in this case.

This means there is no fixed answer to the question "which driver controls this specific USB port on the back of my computer?". It depends on what you plug into that device, and Windows can change which driver is controlling that USB port based on what you plug in.
My System SpecsSystem Spec

 USB controller and hub weirdness, which driver handles which port

Thread Tools

Similar help and support threads
Thread Forum
Wired Xbox 360 Controller Not Responding In Any USB Port
Hi, I've been using a wired Xbox 360 controller periodically for around three years now and have hardly ever had issues with it, until a couple of days ago where it suddenly stopped working. When I plug it into a USB port on my Dell Studio 1749 laptop (running Windows 7 64 bit) nothing happens;...
Missing some driver: SM Bus Controller, PCI Device, Network Controller
Hey I just recently switch my hard drive ( 320gb HDD 5400 rpm ) to a Samsung 840 EVO 250 Gb. I'm currently missing some files and I can't seem to find those drivers help? Btw it's a laptop here the model if you wanted to know : Asus X401A Network Controller ...
Wireless isn't loading as fast. Which driver handles it?
win 7 64x hp I open up internet explorer when starting up or restarting but the wireless doesn't catch up with it so you get a no connection and then you have to refresh after about 5 seconds. Here are what are listed on my device manager but I'm not sure which of these handle this and what driver...
Network & Sharing
understanding USB port, USB hub, Host controller architecture
Lenovo B570 (laptop) Win7 HP, x64 SP1 I am not experiencing any problems. I am just trying to figure out how things work. I am exploring the relationships of the Host Controller, Root Hub, and USB Ports. Any helpful insight would be appreciated. This computer has four USB ports. I plugged...
Hardware & Devices
External 2 Port SATA III Controller
I've come to the conclusion that my current controller card has gone south, thus I'm looking for a replacement. It is simple to compare cards in terms of their basic specs, but even with cards of the same specs, the prices vary widely. Often, the higher priced cards seem to emphasize their...
Hardware & Devices

Our Sites

Site Links

About Us

Find Us

Windows 7 Forums is an independent web site and has not been authorized, sponsored, or otherwise approved by Microsoft Corporation. "Windows 7" and related materials are trademarks of Microsoft Corp.

Designer Media Ltd

All times are GMT -5. The time now is 09:58.
Twitter Facebook Google+