Windows 7: USB device not recognized - but there is no usb device connected

It's recognized in device manager as "Unknown device". But I've not connected anything to pc. Also all of my usb ports are working at 1.1 speed. When I try to connect any device, I get the message "that it could work faster, if i connect it to hi-speed usb port".



Any suggestions?

It could be two unrelated issues.
1. You could have a device that needs a driver.
2. Some motherboards use a mixture of 1.1 and 2.0 ports, so that's the reason for the message.

You could check to see if you can get a hardware id for the device, from the device manager.
If using an Intel board, try Intel® Driver Update Utility

And what happens if in DevManager, you delete the "unknown"?

Nothing. It's appears again after reboot.

when i connect my external hdd
3 of 4 usb ports recognizes the device and shows "it could work faster if you connect it to a 2.0 usb..."
and 1 shows that device is not recognized.

charmk,

Pity. Although that is what I expected.

At various times I marked some articles related to usb problems and, of course, I'll go looking thru them to see if I find anything that fits.

You might viist the Microssoft Troubleshooting site and see if they have a usb troubleshooter and, still a bigger if, if it really solves the problem.

Microsoft Fix it Solution Center: troubleshooting software issues

What will help me is if you fluff out your System Specs, for example, Win 7 is a little bit short for describing the OS.

In the following write-up 3 different info gathers are presented. Two I've used myself. Speccy is simpler and SIW is the motherload of all info about your system. I do recommend running SIW then choosing FILE | Create report file | HTML Save that report for your own records. There will be such things as your licenses, your computer serial number, you computer Model number, detailed info about every piece of hardware on your computer (which might help run down the problem), a list of drivers installed, a list of installed software. The program is free and utterly amazing.
Update your SevenForums System Specs
User CP (3rd item in the top menu bar) |
Your Profile (left-hand column, Edit System Spec

To gather info, use
Speccy - System Information - Free Download
or SIW or the System Info tool,
Use System Info to see your System Specs

Add the word laptop or desktop or netbook to the
“system manufacturer” block.

Provide full windows version info, for example:
MS Windows 7 Ultimate 64-bit SP1

Use the “Other Info” block for Optical Reader,
Mouse, touchpad, wifi adapter, speakers, monitor, etc

Scroll down and click on the SAVE CHANGES button.

updated system specs a little.

Better, although adding the manufacturer and model of yuur computer wouldn't be a bad idea.

Now the bad news is that I don't have a direct answer for you. Somewhere in the deep recesses of my gray matter I recall seeing something about problems with older usb ports, in other words, pre-usb 2.0.