每当您插入USB 鼠标(USB mouse)、键盘、相机或其他设备时，您是否收到“无法识别 USB 设备”错误？(USB device not recognized)我不能没有USB端口，目前我的电脑上有 5 个端口，这样我就可以一次将鼠标、键盘、相机、电话和打印机连接到它上面！
对于那些拥有更多USB小工具的人，您可能已经将USB 集线器(USB hub)连接到您的一个USB端口，以便您可以连接更多设备。大多数情况下，这很好用，但有时您的计算机可能会停止识别USB设备。这个错误的奇怪之处在于端口工作得很好，因为我仍然可以毫无问题地为我的手机(cell phone)充电，但无法使用同一个端口识别我的相机。
在花了很多时间并尝试了一堆不同的方法来解决问题之后，只有一个解决方案最终对我有用。我将首先提到该解决方案，但也会提到其他可能的解决方案，因为第一个解决方案可能无法为每个人解决问题。
此外，如果您的USB 驱动器(USB drive)未显示在您的Windows 计算机(Windows computer)上，请查看我们的YouTube 视频(YouTube video)。
方法 1 – 拔下电脑
那么我最终是如何解决这个问题的呢？好吧，如果你幸运的话，这是一个超级简单的解决方案！先试试这个方法，如果行得通，你会节省很多时间。
只需(Simply)从电源(power supply)上拔下您的计算机。是的，就是这样！请注意，这并不意味着只需使用电源按钮(power button)关闭计算机，因为大多数现代计算机实际上并未完全关闭，主板仍会通电。如果您想远程唤醒计算机等，这有时很有用。
主板是计算机所有硬件（包括USB端口）连接的地方。有时主板需要“重新启动”，因为可能会出现问题，即所有或部分 USB端口突然停止工作。主板上的小型微处理器将重新加载驱动程序，您的USB端口应该有望再次识别设备。
因此，首先使用Windows中的(Windows)关机(Shut Down)选项或按下电源按钮(power button)关闭计算机，然后从墙上插座(wall outlet)拔下(UNPLUG)PC 。让它静置几分钟，然后重新插入。
方法 2 – 更新设备驱动程序
如果Windows无法识别该设备，您可能还会在设备管理器(Device Manager)中看到该设备显示为“未知设备(Unknown Device)”。您可以通过单击开始(Start)并输入devmgmt.msc或转到控制面板(Control Panel)并单击设备管理器来进入( Device Manager)设备(Device Manager)管理器。
在这种情况下，您应该右键单击Unknown Device，单击Properties，然后 单击Driver选项卡，然后单击Update Driver。
如果这不起作用，您也可以尝试从制造商的网站下载设备的驱动程序。如果USB 设备(USB device)只是一个闪存驱动器，那么它可能不是驱动程序问题(driver issue)。但是，如果您要安装USB 打印机(USB printer)、绘图板等，则可能值得下载该特定设备的驱动程序。
方法 3 (Method 3) – 重启和断开 USB 设备(– Restart & Disconnect USB Devices)
您可以尝试的下一件事是断开所有USB 设备(USB device)，然后重新启动机器。重新启动后，尝试连接导致问题的USB 设备。(USB device)
如果那个特定的USB 端口(USB port)无法识别它，请尝试另一个。如果设备被其他USB 端口(USB port)识别，则其中一个USB(USB port)端口可能存在硬件问题(hardware problem)。如果没有USB 端口(USB port)可以识别该设备，请继续阅读，因为它可能是别的东西。
方法 4 – USB 根集线器
您可以尝试的另一件事是打开设备管理器(Device Manager)，展开USB 串行总线控制器(USB Serial Bus Controllers)，右键单击USB 根集线器(USB Root Hub)，然后单击属性(Properties)。
单击电源管理(Power Management)选项卡并取消选中允许计算机关闭此设备以节省电源(Allow the computer to turn off this device to save power)框。如果您列出了多个USB 根集线器(USB Root Hub)，则需要为每个集线器重复这些步骤。
单击确定(Click OK)，然后重新启动计算机。尝试重新连接USB 设备(USB device)并查看它是否被识别。如果没有，请返回每个选项卡的电源管理选项卡并再次选中该框。(power management tab)如果它确实识别设备，则不要选中它们。
方法 5 – 直接连接到 PC
我的一个朋友遇到(mine ran)了这个问题，原因最终是他的USB 集线器(USB hub)。他的电脑上只有三个USB端口，所以他买了一个集线器，可以连接额外的 8 个USB设备。
我想这对他的电脑来说太过分了，它只是偶尔开始无法识别各种设备。卸下集线器并将设备直接连接到计算机后，它工作得很好。
除了减少连接到集线器的项目数量之外，我们还没有真正找到任何其他解决方案来解决这个问题。实际上，另一种解决方案有效，但这意味着必须购买功率更大的新 USB 集线器(new USB hub with more power)。
如果您在使用Windows 8或Windows 8.1时遇到此问题，那么您可能很幸运。Microsoft已发布针对Windows 8无法正确检测USB设备的修复程序。(released a fix)如果运行Windows 8(Windows 8)，请确保安装此修补程序。
方法 6 – USB 疑难解答
如果到目前为止没有任何效果，您可以下载Windows USB Troubleshooter Fixit 工具(Fixit tool)。这是一个适用于Windows XP、Vista和 7 的免费工具。
您可以让疑难解答程序为您解决问题，也可以自己选择修复程序。我只是让它为您解决它们，因为对于新手用户(novice user)来说，这些选择有时会让人感到困惑和技术性。
方法 7 – 更新通用 USB 集线器
如果您在设备管理器中收到(Device Manager)Unknown Device错误，您还可以尝试另一件事。打开设备管理器(Device Manager)，然后展开通用串行总线控制器(Universal Serial Bus Controllers)。
您应该至少看到一个名为Generic USB Hub的项目。在某些计算机上，您可能会看到其中的两个、三个或更多。右键单击第一个并选择Update Driver Software。
弹出更新对话框时，选择Browse my computer for driver software。
然后单击让我从(Let me pick from a list of device drivers on my computer)底部计算机上的设备驱动程序列表中选择。
从列表中选择通用 USB 集线器(Generic USB Hub)。通常，除了那个选项之外，不会列出任何其他内容。单击下一步(Next)，然后在完成安装后单击关闭。(Close)
此时，设备管理器屏幕(Device Manager screen)应该会刷新，并且未知设备仍然存在，或者现在可以识别。如果它仍然显示为无法识别，则对列出的每个通用 USB 集线器重复该过程。(Generic USB Hub)
方法 8 – 卸载 USB 设备
作为最后的手段，您还可以尝试从系统中卸载所有USB设备，然后重新启动。我最后提到了这一点，因为即使Windows应该自动识别USB控制器、集线器和设备，它有时也会失败，最终导致没有USB端口工作。
我有一台有 6 个USB 端口(USB port)的电脑，只有一个端口无法正常工作。我卸载了设备管理器中(Device Manager)USB 串行总线控制器(USB Serial Bus Controllers)下的所有内容并重新启动。我没有重新检测所有内容，而是没有USB 端口(USB port)工作，所以使用这种方法时要小心。
转到设备管理器并开始从(Device Manager)USB Serial Bus Controllers下卸载每个项目。在开始使用任何已经工作的东西之前，请卸载带有感叹号或列为Unknown Device的项目。
方法 9 – 卸载隐藏设备
默认情况下，设备管理器(Device Manager)不显示(t show)已安装到系统中的所有设备。它基本上只显示当前连接的那些。但是，如果您之前安装了USB 打印机(USB printer)，现在不再使用它，它仍然会安装，但不会显示在设备管理器(Device Manager)中。
某些隐藏或幽灵(Certain hidden or ghost) USB设备可能会导致与当前USB设备发生冲突，从而导致此错误。您可以通过首先打开命令提示符(command prompt)然后键入以下两个命令来查看设备管理器(Device Manager)中的隐藏设备：
set DEVMGR_SHOW_DETAILS=1
set DEVMGR_SHOW_NONPRESENT_DEVICES=1
start devmgmt.msc
加载设备管理器(Device Manager)后，您需要单击查看(View)，然后单击显示隐藏的设备。(Show Hidden Devices.)
现在您要扩展成像设备(Imaging Devices)、通用串行总线控制器(Universal Serial Bus Controllers)和未知设备(Unknown Devices)。如果您看到那里列出的任何内容显示为灰色或显示为未知设备，请继续并右键单击它们并选择Uninstall。希望(Hopefully)移除旧设备可以让新设备正常工作。
其他可能的解决方案
如果在此之前没有任何效果，那么可以肯定地说实际硬件可能存在问题。最好的办法是将设备连接到另一台计算机，看看它是否工作。如果不是，那肯定是设备的问题。
Possible Solution #1 – 其他可能的解决方案是尝试使用不同的USB 电缆(USB cable)，如果您身边有一根。如果没有，只需从亚马逊(Amazon)购买新的廉价USB 电缆(USB cable)：A 到 B(A to B)、A 到 Micro B(A to Micro B)、A 到 Mini B(A to Mini B)或 A 到(A to A)A。这是一个相当罕见的问题，但在我从事技术支持的多年中，我已经看到它发生过几次。
Possible Solution # 2 – 另一种可能的解决方案是取出设备，将其连接到另一台机器，如果它正确识别设备，则在重新连接到原始计算机之前将其从该计算机中正确弹出。我已经看到这个问题发生在几个没有正确弹出的闪存驱动器上。将它们连接到另一台计算机并从那里正确弹出后，它们突然开始出现在无法识别它们的原始计算机上。
Possible Solution #3 – 一些人通过更新BIOS幸运地摆脱了这个问题。我已经写过一篇关于更新BIOS(BIOS)是否是个好主意的文章，但在这种情况下，可能值得一试。您也可以进入BIOS并禁用USB，重新启动计算机，然后再次启用USB。您唯一需要确保的是您的计算机上有一个PS2 端口(PS2 port)，否则如果您的键盘和鼠标(keyboard and mouse)是通过USB连接的，则在BIOS中禁用(BIOS)USB后您将无法执行任何操作。
希望上述众多解决方案之一能够解决您的USB 问题(USB problem)。如果没有，请发表评论，我会尽力提供帮助。享受！
How to Fix USB Device Not Recognized in Windows
Are you getting a “USB device not recognized” error whenever you plug in a USB mouse, keyboard, camera, or other device? I can’t live without USB ports and currently have 5 ports on my computer so that I can connect my mouse, keyboard, camera, phone, and printer to it all at once!
For those of you with even more USB gadgets, you probably have connected a USB hub to one of your USB ports so that can you connect even more devices. Most of the time this works great, but occasionally your computer might stop recognizing USB devices. The odd thing about this error is that the ports are working just fine, as I was able to still charge my cell phone without a problem, but couldn’t get my camera recognized using the same port.
After spending a lot of time and trying a bunch of different ways to fix the problem, only one solution ended up working for me. I’ll mention that solution first, but will also mention the other possible solutions, as the first solution may not fix the problem for everyone.
Also, check out our YouTube video if your USB drive is not showing up on your Windows computer.
Method 1 – Unplug Computer
So how did I finally fix the problem? Well, if you are lucky, it’s a super simple solution! Try this method first and if it works, you’ll have saved a lot of time.
Simply unplug your computer from the power supply. Yes that is it! Note that this does not mean just turning off your computer using the power button because most modern computers don’t actually turn off completely and the motherboard will still get power. This is useful sometimes if you want to remotely wake up a computer, etc.
The motherboard is where all of hardware of the computer connects to, including the USB ports. Sometimes the motherboard needs to be “rebooted” because things can go wrong, i.e. all or some USB ports suddenly stop working. The small microprocessor on the motherboard will reload the drivers and your USB ports should hopefully be recognizing devices again.
So first turn off your computer using the Shut Down option in Windows or pressing the power button and then UNPLUG the PC from the wall outlet. Let it sit for several minutes and then plug it back in.
Method 2 – Update Device Driver
If Windows is not able to recognize the device, you may also see in Device Manager that the device shows up as an “Unknown Device”. You can get to Device Manager by clicking on Start and typing in devmgmt.msc or by going to Control Panel and clicking on Device Manager.
In that case, you should right-click on Unknown Device, click on Properties, then the Driver tab and then click Update Driver.
If this doesn’t work, you can also try to download the driver for your device from the manufacturer’s website. If the USB device is just a flash drive, then it’s probably not a driver issue. However, if you are installing a USB printer, drawing pad, etc, then it might be worth downloading the driver for that specific device.
Method 3 – Restart & Disconnect USB Devices
The next thing you can try is to disconnect all USB devices and then restart the machine. once you have restarted, try to connect the USB device that was causing the problem.
If that particular USB port doesn’t recognize it, try another one. If the device is recognized by a different USB port, there could be a hardware problem with one of the USB ports. If no USB port recognizes the device, then keep reading because it’s probably something else.
Method 4 – USB Root Hub
Another thing you can try is to open Device Manager, expand USB Serial Bus Controllers, right-click on USB Root Hub and then click on Properties.
Click on the Power Management tab and uncheck the Allow the computer to turn off this device to save power box. If you have more than one USB Root Hub listed, you need to repeat these steps for each one.
Click OK and then restart your computer. Try to reconnect the USB device and see if it is recognized. If not, go back to the power management tab for each one and check the box again. If it does recognize the device, then leave them unchecked.
Method 5 – Connect Directly to PC
A friend of mine ran into this issue and the cause ended up being his USB hub. He only had three USB ports on his computer, so he bought a hub where he could connect an additional 8 USB devices.
I guess this proved too much for his computer and it just started sporadically not recognizing various devices. After removing the hub and connecting the device directly to the computer, it worked just fine.
We haven’t really been able to find any other solution to this problem other than reducing the number of items connected to the hub. Actually, one other solution worked, but it meant having to buy a new USB hub with more power.
If you are having this problem with Windows 8 or Windows 8.1, then you might be in luck. Microsoft has released a fix for Windows 8 not detecting USB devices properly. Make sure to install this hotfix if running Windows 8.
Method 6 – USB Troubleshooter
If nothing has worked so far, you can download the Windows USB Troubleshooter Fixit tool. It’s a free tool that works with Windows XP, Vista and 7.
You can either have the troubleshooter fix the problems for you or select the fixes yourself. I would just let it fix them for you since the choices can sometimes be confusing and technical for the novice user.
Method 7 – Update Generic USB Hub
If you are getting the Unknown Device error in Device Manager, you can also try one other thing. Open Device Manager and then expand Universal Serial Bus Controllers.
You should see at least one item called Generic USB Hub. On some computers, you might see two, three or more of these. Right-click on the first one and choose Update Driver Software.
When the update dialog pops up, choose Browse my computer for driver software.
Then click on Let me pick from a list of device drivers on my computer at the bottom.
From the list, select Generic USB Hub. Normally, there won’t be anything else listed except for that one choice. Click Next and then click Close once it finishes installing it.
At this point, the Device Manager screen should refresh and either the unknown device will still be there or it may now be recognized. If it’s still showing as not recognized, then you repeat the process for each Generic USB Hub listed.
Method 8 – Uninstall USB Devices
As a last resort, you can also try uninstalling all USB devices from your system and then restarting. I mention this last because even though Windows is supposed to automatically recognize the USB controllers, hubs and devices automatically, it can sometimes fail and you’ll end up with no USB ports working.
I had a computer with 6 USB ports and only one port would not work properly. I uninstalled everything under USB Serial Bus Controllers in Device Manager and restarted. Instead of re-detecting everything, I was left with no USB port working, so be careful when using this method.
Go to Device Manager and start uninstalling each item from under USB Serial Bus Controllers. Before you start with anything that is already working, uninstall the items with exclamation points or that are listed as Unknown Device.
Method 9 – Uninstall Hidden Devices
By default, Device Manager doesn’t show all devices that have been installed to the system. It basically only shows the ones that are currently connected. However, if you installed a USB printer earlier and now no longer use it, it will still be installed, but won’t show up in Device Manager.
Certain hidden or ghost USB devices can cause conflicts with current USB devices and therefore lead to this error. You can view hidden devices in Device Manager by first opening a command prompt and then typing the following two commands:
set DEVMGR_SHOW_DETAILS=1
set DEVMGR_SHOW_NONPRESENT_DEVICES=1
start devmgmt.msc
Once Device Manager loads, you need to click on View and then click on Show Hidden Devices.
Now you want to expand Imaging Devices, Universal Serial Bus Controllers and Unknown Devices. If you see anything listed there that is greyed out or that says unknown device, go ahead and right-click on them and choose Uninstall. Hopefully, removing the older devices will allow the newer devices to work properly.
Other Possible Solutions
If nothing has worked until this point, it’s pretty safe to say there could be a problem with the actual hardware. The best thing to do is to connect the device to another computer and see if it works or not. If not, then it’s definitely an issue with the device.
Possible Solution #1 – The other possible solutions are to try a different USB cable, if you have one lying around. If not, just buy a new cheap USB cable from Amazon: A to B, A to Micro B, A to Mini B, or A to A. This is a fairly rare problem, but I have seen it occur a few times over my many years doing technical support.
Possible Solution # 2 – Another possible solution is to take the device, connect it to another machine and if it does recognize the device properly, to then eject it properly from that computer before reconnecting it to the original computer. I’ve seen this problem occur with several flash drives that were unplugged without ejecting properly. After connecting them to another computer and ejecting them properly from there, they suddenly started to show up on the original computer that was not recognizing them.
Possible Solution #3 – A few people have had luck getting rid of this problem by updating the BIOS. I’ve already written an article about whether it’s a good idea or not to update the BIOS, but in this case, it might be worth a try. You can also go into the BIOS and disable USB, restart the computer and then enable USB again. The only thing you need to make sure is that you have a PS2 port on your computer, otherwise you won’t be able to do anything once you disable USB in the BIOS if your keyboard and mouse are connected via USB.
Hopefully, one of the many solutions above will solve your USB problem. If not, post a comment and I’ll try to help. Enjoy!
