I have a P4 with Win XP Pro installed, two USB ports at the front and two at the back. Since yesterday I,m unable to use my Flash Drive or the Card Reader. Device Manager says "Uknownown Device" when I expend the Universal Serial Bus Controllers. I checked the wires and everything sims to be plugged in and OK. When I try to update the driver it says "the best driver is already installed". The puzzle is why is it that the front and the rear ports are not picking up the USB devices? Is it the motherboard? I'm sure it can't be the USB ports itself, I hardly ever used the two ports at the rear of the computer (built on to the MB). I tried the Registry Mechanic but it's not picking up unything? Anyone, any suggestions?

Since your Device Manager is identifying an Unknown Device under your USB entry, it probably means that the drivers for your USB Universal Host Controller or for your USB Root Hub are not installed.

Is this a Brand Name machine or a custome built machine.
If it is Brand Name, use the resources of your Computer Manufacturer's website to discover what USB drives should be installed. You should also be able to download any missing Driver that you identify there.

It is remotely possible that your ChipSet Drivers for USB have become compromised. You should be able to download for installation your entire Chipset Drivers package or any part (audio, video, USB) that you wish from your Computer Manufacturer's site.

Next, use your Systems Configuration Utility to scan for missing or corrupt System Files
to do this:
Start - Run - (type) sfc /scannow

Have your Windows operating system installation CD handy in case SFC needs to copy and replace any missing or corrupted System File.

Please help us Rule Out any possible causes that only you would know about.
For instance: New hardware or software installations, new downloads, recent malware infection?
Do the USB ports fail for "all" USB devices, or just some that your try to plug in?
Many USB devices are powered by the USB port itself, for instance memory sticks.
Other USB devices have other power sources and just exchange data over USB port, for instance Printers.
Are some USB devices working and some not?

What USB Devices do you have installed on your machine?
For instance, you refer to Flash Drive and Memory Card (for what kind of Camera?), what other USB Devices?

Let us know how you are progressing.

Best Regards

This post has been edited by dough: Jun 10 2006, 07:24 PM

I'm using Belarc Adviser, I have most of the details here in front of me, some are very personal, I cannot copy and paste everything but some details I can.
I am at a Diploma level (final year) and I am experimenting with various OS including Linux. I tried Win 2003 it also is not picking up the Kingston Flash Drive 256 MB nor the MultiCard Reader (9 in 1 - Microdia) I'm using a DX card to transfer photos from my Fuji S5000 Camera, I also tried the new USB Keyboard I just bought, and it WORKS for some reason! The Keyboard works with the Win XP and the Win 2003 in this computer. All of the devices work in all other computers.
I do not remember installing new devices in this computer, I might have been trying out some softwares, I do that often but cannot recall which ones. The only device I installed was the DVD burner about two weeks ago but all of the USB ports worked fine for a week or so.
The Bus Adapters are Sis 7001 PCI to USB Open Host Controller (2X) and a Sis7002 USB 2.0 Enhanced H.C, if that means anything!
I will be looking for new ChipSet Drivers for USB as you suggested, I've done the Scan but I can't see any difference.

This post has been edited by Hex: Jun 11 2006, 12:57 AM

Hi Hex,

Couple of things.

You are wise to not post the full information from Belarc Advisor or any similar utility like Everest 2.20, without editing, since they generally report your IP address. However, if you do decide to post such information, you can easily "edit" the information by Copy/Paste and X'ing out the information you do not want to make public. For Instance, IP xx.xxx.xx.xxx Then you are safe.
Second, since you are close to a Diploma, you're way more educated than me, so take my recommendations with "a grain of salt".

Have you consulted the Kingston website?
http://www.kingston.com/support/faqs/dmr/media.asp

You might get some information from the Microdia website, Here:
http://www.microdia.com/ebiz/jsp/site/supp..._cardreader.jsp

For the Microdia device, it seems that some may need to be inserted "face up" and others "face down"

It may take a few moments for your system to "recognize" the device.

If you reboot your system with the device plugged in, does the boot proceedure "count" the memory available in your USB device.

You may need to change a CMOS setting to recognize the USB memory device.

I'm still curious about the "unknown device" that you find in the expanded USB Devices.
Does your Belarc Advisor list more USB controller devices than your Device Manager?
If so, you may need to install the driver by "updating and selecting device from a list" to find the specific device.

Best Regards

Afterthought.........

Google your two bus adapters.
Is the first one appropriate to Windows ME, but not for XP?
Is the second one for Linux but not for Windows?

You may still need to install the Chipset Drivers appropriate to Windows XP in order to utilitize these USB devices.

I'm not to sure about that, with the diploma's one step forward it seems to be dragging me ten steps backward. I've been having so much problems with computer it's not funny. I feel sorry for those who know less then me,
I think I'd be better off selling my computer and buying a typewriter and I might do that one day!

I've tried reinstalling all drivers from the CD that came with the motherboard when I bought the computer but no luck, can't see any difference, only the new USB Keyboard works. I should be able to find new set of front USB ports somewhere. For now, I guess I'll have to copy files on to a CD then from the CD, if they're more then 1.4 Mb.

You've done a bunch of work on this, and the solution is probably just hiding there in plain site, but we haven't noticed/recognized it yet.

In the meantime, since you have reasonable need for USB devices, you might want to pick up a USB 2.0 PCI Card. I bought one with 4 ports for about $14.00.

Couple of good places to shop:
www.newegg.com
www.tigerdirect.com

Best Regards

Hi Dough,
Yesterday I bought a 4 port Hub for $4, not that I needed one but I bought it anyhow, I plugged it into the front USB port that wasn't recognising the Kingston Flash drive and guess what happened? It worked!!! The only objection it had, saying that the "High speed device was plugged into low speed port"
Can you make anything out of it, does that make sense to you? I'm still lost!

erm? perhaps your new Hub accommodates USB 2.0 and the USB terminal at the front of your machine is only running at USB 1.0.?

If that is in fact the case, (USB 1.0) that could possibly explain the difficulties you were having with other devices plugged into your USB port.

But then, I think you already did the trouble-shooting and driver updates etc. to assure that the port was functioning properly. But please remember that USB 1.0 will never operate at USB 2.0. For instance, you can't improve USB 1.0 by loading it with an updated driver. And if the USB port at the front of your machine is malfunctioning, any Hub you add to multiply the number of devices you can attach to that port, will also suffer the same malfunction of the USB Port itself.

I guess I'm still lost on this one.

What I meant by "puchase a USB 2.0 card" was to actually purchase a USB PCI card to install into a PCI slot to add new USB 2.0 ports at the back of your machine.

Hope you get this one sorted.

Best Regards