When I plug in certain USB devices, sometimes my PC doesn't recognize them.
There are certain USB devices it always recognizes. There are others that it
never recognizes. Then there's one that it was recognizing, but it no longer
is.

Ken W wrote:[color=blue]
> When I plug in certain USB devices, sometimes my PC doesn't recognize them.
> There are certain USB devices it always recognizes. There are others that it
> never recognizes. Then there's one that it was recognizing, but it no longer
> is.[/color]
I had the same problem.
I tried several fixes, but only certain ones worked.
Hope that helps.

I had a similar problem with a 16 gb USB drive. And it was dog slow. I
formatted it (just like any other drive) with NTFS and no longer had any
trouble and it flys.

"spamme0" <spamme9******.com> wrote in message
news:gle2u9$kah$1@news.motzarella.org...[color=blue]
> Ken W wrote:[color=green]
> > When I plug in certain USB devices, sometimes my PC doesn't recognize[/color][/color]
them.[color=blue][color=green]
> > There are certain USB devices it always recognizes. There are others[/color][/color]
that it[color=blue][color=green]
> > never recognizes. Then there's one that it was recognizing, but it no[/color][/color]
longer[color=blue][color=green]
> > is.[/color]
> I had the same problem.
> I tried several fixes, but only certain ones worked.
> Hope that helps.[/color]

Here are some methods helping the computer to recognize the USB devices
plugged in.

Method 1: Initiate recognition of the USB device by using Device Manager
To initiate recognition of the USB device by using Device Manager, follow
these steps:
Click Start, click Run, type Devmgmt.msc, and then click OK. The Device
Manager window opens.
Click to select your computer as the location for the scan.
On the Action menu, click Scan for hardware changes.

Windows recognizes the new device.
Close the Device Manager window.
If this method resolves the issue, you are finished.

If this method does not resolve the issue, go to method 2.
Back to the top
Method 2: Disable power management of the USB hub
Note If you perform the following procedure, you may also reduce the battery
life on a portable computer.

Use this method if method 1 does not work. To disable power management of
the USB hub, follow these steps:
Click Start, click Run, type Devmgmt.msc, and then click OK. The Device
Manager window opens.
Expand Universal Serial Bus controllers.
Right-click a USB Root Hub in the list, and then click Properties. The USB
Root Hub Properties dialog box is displayed.
Click the Power Management tab.
Click to clear the Allow the computer to turn off this device to save power
check box, and then click OK.
Repeat steps 3 through 6 for each USB Root Hub in the list.
On the Action menu, click Scan for hardware changes.

Windows recognizes the new device.
Close the Device Manager window.
If this method does not resolve the issue, go to method 3.
Back to the top
Method 3: Restart the computer

Other things to try: identify the version of the USB device and the port on
your computer and make sure they are the same. It is said that USB 2.0 and
USB 1.1 or 1.0 ports and devices cooperate with each other but sometimes it
depends on the features of your devices. Make sure the current drivers are
installed and the devices are with plenty power supply if there are any. It
is better not to use over 3 USB devices on a single computer at the same
time.

To know if my PC has USB 2.0:
You can identify whether your PC has Hi-Speed USB or not relatively easy.
Open Device Manager and expand the Universal Serial Bus section. There
should be an "Enhanced" USB host controller present.

"Ken W" <KenW@discussions.microsoft.com> wrote in message
news:34372CA0-4ACA-4997-A242-349922E5B81C@microsoft.com...[color=blue]
> When I plug in certain USB devices, sometimes my PC doesn't recognize
> them.
> There are certain USB devices it always recognizes. There are others that
> it
> never recognizes. Then there's one that it was recognizing, but it no
> longer
> is.[/color]

Method 1 resolved the problem before, but it's come up again. When I've run
through Method 1 again, the light on my USB device comes on and it seems to
be doing something. However, it doesn't appear at all with a drive letter in
"My Computer".

Also, in the device manager, one of the items called "USB Mass Storage
Device" has a yellow exclamation point to it. The error says "Windows is
uninstalling this device. (Code 21)". However, that error has been there a
long time and nothing seems to be uninstalling at all.


"donald huang" wrote:
[color=blue]
> Here are some methods helping the computer to recognize the USB devices
> plugged in.
>
> Method 1: Initiate recognition of the USB device by using Device Manager
> To initiate recognition of the USB device by using Device Manager, follow
> these steps:
> Click Start, click Run, type Devmgmt.msc, and then click OK. The Device
> Manager window opens.
> Click to select your computer as the location for the scan.
> On the Action menu, click Scan for hardware changes.
>
> Windows recognizes the new device.
> Close the Device Manager window.
> If this method resolves the issue, you are finished.
>
> If this method does not resolve the issue, go to method 2.
> Back to the top
> Method 2: Disable power management of the USB hub
> Note If you perform the following procedure, you may also reduce the battery
> life on a portable computer.
>
> Use this method if method 1 does not work. To disable power management of
> the USB hub, follow these steps:
> Click Start, click Run, type Devmgmt.msc, and then click OK. The Device
> Manager window opens.
> Expand Universal Serial Bus controllers.
> Right-click a USB Root Hub in the list, and then click Properties. The USB
> Root Hub Properties dialog box is displayed.
> Click the Power Management tab.
> Click to clear the Allow the computer to turn off this device to save power
> check box, and then click OK.
> Repeat steps 3 through 6 for each USB Root Hub in the list.
> On the Action menu, click Scan for hardware changes.
>
> Windows recognizes the new device.
> Close the Device Manager window.
> If this method does not resolve the issue, go to method 3.
> Back to the top
> Method 3: Restart the computer
>
> Other things to try: identify the version of the USB device and the port on
> your computer and make sure they are the same. It is said that USB 2.0 and
> USB 1.1 or 1.0 ports and devices cooperate with each other but sometimes it
> depends on the features of your devices. Make sure the current drivers are
> installed and the devices are with plenty power supply if there are any. It
> is better not to use over 3 USB devices on a single computer at the same
> time.
>
> To know if my PC has USB 2.0:
> You can identify whether your PC has Hi-Speed USB or not relatively easy.
> Open Device Manager and expand the Universal Serial Bus section. There
> should be an "Enhanced" USB host controller present.
>
> "Ken W" <KenW@discussions.microsoft.com> wrote in message
> news:34372CA0-4ACA-4997-A242-349922E5B81C@microsoft.com...[color=green]
> > When I plug in certain USB devices, sometimes my PC doesn't recognize
> > them.
> > There are certain USB devices it always recognizes. There are others that
> > it
> > never recognizes. Then there's one that it was recognizing, but it no
> > longer
> > is.[/color]
>[/color]