Basic Troubleshooting Steps for the Plugable USB-BT4LE Bluetooth Adapter

The Plugable Bluetooth adapter works great in Windows, but Bluetooth is very complex, and many different issues can crop up that keep it from working correctly. This page identifies some of the common problems that can occur, and provides steps for identifying the most likely causes and solutions.

In our years of experience troubleshooting this adapter, it is usually not a problem with the adapter itself. Most problems are related to the driver or Bluetooth software, pairing issues, or environmental conditions such as radio interference. However, if it looks like your adapter is having problems and the steps below don’t help, please don’t hesitate to contact us at We are always happy to help and will send a replacement immediately if the adapter is faulty for some reason.

The troubleshooting techniques on this page are completely optional. We are always happy to help with any questions or issues! Just contact as at

An Overview of Bluetooth Operation

As mentioned above, the Bluetooth adapter itself is pretty simple. It takes packets of data from your computer, encodes them into a radio signal, and sends them to your peripheral device. It receives radio packets from the peripheral device, decodes them into data packets, and sends them to the computer. This process can suffer in two ways: radio problems that block or corrupt the radio signal and problems with the hardware of the adapter itself. Adapter hardware problems will usually show up when the adapter fails to work at all.

Radio signal problems tend to show us as reduced range, frequent disconnections, and lag. In our experience, most radio problems are caused by radio noise coming from components in the host computer, especially poorly-shielded USB 3.0 ports and unshielded components in desktop computers. Radio problems can also be caused by objects between the adapter and the receiver blocking and absorbing the signal. Having a large number of strong Wi-Fi signals in the area can also cause radio problems, since Wi-Fi and Bluetooth use the same radio frequencies, but Wi-Fi is much more powerful.

The Bluetooth adapter gets its data packets from your computer’s USB controller through the USB port. A physical problem with the USB port will cause malfunctions. The easiest way to identify this is to try another port. Out of date, missing, or corrupted USB controller software will cause the adapter to malfunction regardless of the port it is plugged into.

When you plug your adapter into a USB port, the computer queries it for information about what kind of device it is. It then searches for a driver for your device. A driver tells Windows how to communicate with a hardware device and how to interpret the information it sends and receives. Using a wrong or corrupted driver means that Windows is not able to communicate with a device properly. Having drivers present for more than one Bluetooth device also causes problems because Windows does not know which one to communicate to.

Windows creates the data packets to send to the Bluetooth adapter in its Bluetooth stack. This is software arranged in layers that processes and prepares Bluetooth data for particular purposes. It also receive data from peripheral devices connected through the Bluetooth adapter and shapes into data that can be understood by other programs in Windows. The stack has separate modules, called profiles, that standardize how Windows communicates with particular Bluetooth device types, such as A2DP (stereo audio), HID (human interface devices like keyboards and mice), HSP/HFP (headsets and hands-free devices), and many more.

Different Windows versions come with different profiles. For example, while Windows 8 through 10 support Bluetooth audio, in Windows 7, Windows audio profiles and drivers have to be installed with third-party software, such as the driver packages on the Plugable website or the CD that comes with the adapter. Missing, corrupted, or incorrect profile versions will cause pairing and connection problems. Often a driver error for the peripheral will be reported in this case.

Windows establishes a connection with a Bluetooth peripheral through a pairing process. Typically, Windows acts as a host and the peripheral is put into pairing mode, where it advertises its presence to any nearby Bluetooth devices. Windows sees the peripheral and establishes low-level communication where it finds out the devices name and what kind of device it is. It displays the device information in the settings window that appears when you want to add a Bluetooth device.

When you tell Windows to pair and connect to a Bluetooth peripheral, Windows establishes a connection and asks the device what profiles it uses and what kind of security it supports. If Windows has those profiles available it uses them as guidelines on communicating with the device. It goes through the security protocol required by the device, sets up the connection, and is ready to communicate with it according to the purpose of that device.


Click your symptom below to go to the section that describes that problem. If you don’t see your symptom on the list or the suggested solutions don’t work, don’t hesitate to contact us at We are happy to help.

This situation is different from the case where the driver installs, but the adapter doesn’t recognize your Bluetooth device when you go to connect.

Things to check in all Windows versions

Does a blue light come on inside the adapter when you plug it in?
If not, try other ports on the computer to see if you get the same result. If the adapter is plugged into a hub or extension cable, try plugging it directly into the computer. If a blue light still doesn’t come on inside the adapter, restart the computer and try again. If the blue light still doesn’t shine, the adapter is likely faulty. Please contact us at for a replacement.

Is the USB device connected sound rapidly followed by a disconnected sound, sometimes over and over?
There is likely an intermittent connection issue ether in the USB port or the adapter. Remove the adapter from any hub or USB extension cable, and connect directly to a USB port on the computer. Try other USB ports on your computer. If the issue continues, the adapter may be malfunctioning. Contact us at to troubleshoot further.

Was Windows able to install the driver?
Open Device Manager. When it opens, click the Bluetooth or Bluetooth Radios section. The Plugable adapter should show up as “Broadcom BCM20702 Bluetooth 4.0 USB Device.” If you don’t see it, check Other Devices. If you see “BCM20702A0” then the computer found the adapter, but was not able to install the drivers. If you haven’t already, try downloading and installing the appropriate driver from our website.

Sometimes an overzealous anti-virus or anti-malware program will block new drivers from installing. Temporarily disable your antivirus or anti-malware programs, and try again.

If you are installing on a work computer, it is possible that your computer is on a domain and driver installation is blocked by your company’s IT staff. Contact them for assistance.

Driver issues can often be identified and resolved using the advanced troubleshooting techniques. You can also contact us at We are always happy to help.

Information on specific Window versions

Windows 10

When you plug your Plugable Bluetooth adapter into a Windows 10 computer, Windows Update is supposed to immediately download and install the correct driver from the Microsoft driver server. However, there are times when Windows Update fails to do this because it can’t reach the server, is disabled, or downloads the wrong driver. If Windows 10 hasn’t installed the driver, we recommend downloading and installing the appropriate driver from our webpage. If this doesn’t help, there may be a driver conflict or other issue. You may want to try the advanced troubleshooting steps, or just contact us at for help.

Windows 7, 8, and 8.1
Although Windows should automatically download a driver for these Windows versions, that driver has limited Bluetooth support, and we recommend downloading and installing the appropriate driver package from our website.

Windows XP and Vista
Windows XP and Vista computers will not automatically install drivers. When the adapter is plugged in, a message saying Found New Hardware or Installing device driver software should be displayed, but the installation will not succeed. This is not a problem. Install the software from the CD or download the appropriate driver file from our website.

Things to check

Is the pairing process working?

In many cases when a Bluetooth peripheral device, such as headphones, speaker, keyboard, or mouse won’t immediately connect or won’t appear in the Bluetooth devices window during pairing, something has gone wrong with the pairing process.

Pairing an audio device

To make sure the pairing process has gone correctly when connecting audio devices, try our step-by-step connection process. Even if your device doesn’t connect, this can help identify the problem. If the step-by-step process doesn’t work, please contact us at and let us know what step it failed at. We can help.

Pairing a keyboard or mouse

Here are some tips for pairing a keyboard or mouse:

  • Make sure the keyboard or mouse is compatible. See below for information about incompatible devices.
  • Turn off Bluetooth on any devices the keyboard or mouse have previously been connected with. This keeps them from reconnecting to that device instead of your computer.
  • Some keyboards require authentication with a PIN. Typically, Windows will display a random number and ask you to type it on the keyboard. In some cases, Windows will display a dialog box with a space to type a PIN. If this happens, check your keyboard’s user guide for the PIN or try 0000 or 1234. PINs are also required by some mice.

Is the device I’m trying to connect a Bluetooth device?

Many wireless devices, especially keyboards and mice, use a proprietary protocol instead of Bluetooth to connect with your computer. Many are made by Logitech and Microsoft. If your device comes with its own dongle, it is probably not Bluetooth. If you are not sure about it, find the model number (typically on a sticker on the bottom) and search for its specifications on the internet. A Bluetooth device will clearly say Bluetooth, while others won’t. Although rare, some wireless headphones also use proprietary dongles and won’t connect via Bluetooth. The good news about these devices is that you can typically use their dongles at the same time as the Plugable Bluetooth dongle without causing interference.

Is my keyboard or mouse supported in Windows 7?

Keyboards and mice that use Bluetooth Low Energy (also called Bluetooth Smart or Bluetooth 4.x) will not work in Windows 7. While our adapter supports Blueooth 4.0, Windows 7 doesn’t. Examples are the Microsoft Designer Mouse and Keyboard, the Microsoft Arc Touch, the Logitech Master MX mouse, the Surface Sculpt Ergonomic keyboard, and others. Always check the manufacturer’s website for compatibility with Windows 7.

Bluetooth 4.0 considerations
Bluetooth 4.0, also called Bluetooth Smart, is supported by the Plugable Bluetooth adapter in Window 8 and later. It is used in many sports-oriented or portable devices like fitness monitors, heart rate monitors, bicycle trainers, and some recent keyboards and mice. It uses a connection method called Bluetooth Low Energy (BLE) that saves battery power on these devices.

These devices can be tricky because BLE works differently than than “Classic” Bluetooth. With Classic Bluetooth, peripheral devices use standard profiles stored in the computer’s Bluetooth software to tell the computer what they are and how they work. For example, nearly all Bluetooth headphones use the A2DP profile. Since nearly all Bluetooth adapters support A2DP, the headphones are pretty sure to connect with any Bluetooth-enabled computer or mobile device. During connection the headphones request the A2DP profile, and the profile tells the computer how to interact with it.

BLE acts at a more basic level. While there are a few BLE profiles, typically the interaction between the device and computer is controlled by a Windows app specifically designed to work with that device. If no Windows app exists for the device or the necessary app has not been installed, Windows will be able to connect to the Bluetooth device, but won’t know how to communicate with it.

Windows 7 doesn’t support BLE at all, and support is weak in Windows 8 and 8.1. Many devices that use BLE have apps available only for Windows 10. Often an app exists for Android and iOS devices, but not for Windows. As always, be sure to check compatibility with your Windows version and check the device maker’s website or contact them directly if you have questions about Windows support.

Finally, many Bluetooth audio devices claim they are Bluetooth 4.0, 4.1, or 4.2. This is typically a marketing ploy. While such audio devices may be compliant with those standards, Bluetooth 4.0 and higher are too slow for streaming audio. Headphones and other audio devices actually use the Classic Bluetooth A2DP and HSP/HFP profiles for sound, and should work with any Bluetooth-enabled device that supports Bluetooth 2.1+EDR, which includes nearly all BLuetooth-enabled devices made in the last 10 years.

Limited range, skipping in audio, and lag between audio and video or between input and on-screen action in games are typical signs that the Bluetooth radio signal is not making it consistently to and from your receiving device.

The range of the Plugable Bluetooth adapter is specified at 10 meters, and that is the minimum we require when we test them here. The most common reason for shorter range, besides obstacles like walls and floors, is radio interference. In order to save battery power in portable devices, Bluetooth signals are weak compared to other devices in the 2.4 GHz band, such as Wi-Fi, and are easily overwhelmed by interference.

Audio skipping happens when the strength of the interference suddenly rises, while lagging is often caused by the input device having to resend input that was degraded before arriving at the computer.

Things to check to determine if radio interference is the issue

1. Is the adapter plugged into a USB 3.0 port? Many poorly shielded USB 3.0 ports leak radio interference in the 2.4GHz band. If so, moving the adapter to a USB 2.0 port or using a USB 2.0 extension cable to move it away from the USB 3.0 port usually helps a lot. Something like this:

2. Are there a lot of Wi-Fi access points around? Bluetooth is much weaker than Wi-Fi, but compensates by avoiding frequencies used by nearby access points. However, if there are a lot of Wi-Fi access points nearby using all the available frequencies, Bluetooth has nowhere to go and the signal will be degraded. Interference can also be caused by cordless phones, wireless video cameras, baby monitors, and microwave ovens.

3. Is the Plugable Bluetooth adapter plugged into the back of a desktop computer? There are many sources of radio interference in a computer, and being in the rear exposes the adapter to them, while the metal and plastic bulk of the computer acts as a shield between the adapter and the devices it is communicating with. Moving the adapter to a port on the front or using an extension cable as above often helps a lot.

4. Check the battery power or charge level on your Bluetooth peripheral device. An exhausted battery or weak charge can can cause skipping or disconnection problems.

If none of these seem to apply, please contact us at We are happy to help and can test a replacement here for 10-meter range and send it to you.

Distorted sound can be caused by various issues, but if the sound is muddy and thin in your stereo headphones or speaker, the likely cause is the computer treating them as a telephone headset instead of as a stereo device. If you experience other kinds of distortion, please contact us at

In Bluetooth, your computer makes profiles available which control how the computer and your device communicate with each other. When you connect a device, it tells the computer which profiles it can use, and the computer loads those profiles for it. There are two commonly used audio profiles in Bluetooth: A2DP and HSP/HFP. A2DP provides one-way CD-quality output through stereo headphones and is meant purely for listening. HSP/HFP, which stands for Headset Profile/Hands-Free Profile, was designed for two-way communication between your phone and a headset or automotive hands-free device. Since they were developed for telephone use and not listening to music, they output only telephone-quality mono sound.

Since many headphones and speakers incorporate a microphone and can be used to connect to a telephone or to communications programs like Skype on your computer, they support both the A2DP and HSP/HFP profiles. Sometimes the computer uses the telephone-quality HSP/HFP profile, even when you are listening music and not using the microphone. This results in muddy and thin sound.

To check your settings in Windows, do the following:

1. Right-click the speaker icon at the lower-right of your screen near the clock.

2. Select Playback Devices. The Sound window will open on the Playback tab.

3. Find your headphones or speaker on the list. You may see two listings for your device, for example Headphones or Speaker and Headset. The Headphones or Speaker listing may also say Stereo or A2DP. Right-click the Headphones or Speaker listing, then select Set as Default Device. This should cause high-quality sound to play through your headphones or speaker, although sound will return to telephone quality when using two-way communication with the microphone. If two-way communication doesn’t work, right-click the Headset listing and select Select as Default Communications Device.

Since the selection of the default device is determined by your sound software, in some computers you may have to redo this setting every time you connect your Bluetooth device.

While Windows is supposed to use your Bluetooth speakers or headphones as the default audio device when you connect them, in many Windows computers the software for the sound card overrides this and keeps the computer speaker output as the default even when a Bluetooth device is connected.

Here is how to set your Bluetooth device as the default audio device.

1. Right-click the speaker icon at the lower-right of your screen near the clock.

2. Select Playback Devices. The Sound window will open on the Playback tab.

3. Find your headphones or speaker on the list. You may see two listings for your device, for example Headphones or Speaker and Headset. The Headphones or Speaker listing may also say Stereo or A2DP. Right-click the Headphones or Speaker listing, then select Set as Default Device. This should cause high-quality sound to play through your Bluetooth headphones or speaker.

Since the selection of the Default device is determined by your sound software, in some computers you may have to redo this setting every time you connect your Bluetooth device.

The Plugable Bluetooth adapter is compatible with iTunes in Windows, but iTunes doesn’t work with Bluetooth the way most programs do. You have to specifically allow Bluetooth playback in the iTunes preferences. Here is how to do it:

  1. Open iTunes and click the little black and white square icon in the upper-left corner.
  2. Click Preferences and click on the Playback tab at the top of the pop-up window.
  3. Near the bottom of the window you’ll see Play Audio Using:, open the dropdown menu next to it and select Direct Sound.
  4. Click OK and close the pop-up window.
  5. Restart iTunes.

You should now be able to play music through your Bluetooth headphones.

Please note: Bluetooth transfer to non-Apple computers is not supported in Apple mobile devices like the iPhone and iPad.

For many reasons, Bluetooth is not the ideal medium for transferring files because it is slow and subject to radio interference. If possible, it is always better to use a USB cable to connect your device to your computer and transfer through it.

However, in some situations Bluetooth is the best choice. When using it, here are some suggestions that may help:

1. When initiating the transfer from the sending device, a confirmation screen will appear on the receiving device involved in the transfer. In almost all cases where the transfer gets set up, but fails almost immediately, it is because the confirmation message wasn’t accepted quickly enough. It is really easy to miss the message. On Windows computers the screen flashes briefly in the notification area near the clock. It is a good idea to keep your eye there when you initiate the transfer so you don’t miss it. In Android devices, a message may briefly appear on the screen, but you should be able to see it by pulling down the notifications. Bluetooth transfer to Windows computers is not possible from iOS devices like iPhones and iPods.

2. If you have troubles setting up Windows to send or receive the transfer, We recommend using fsquirt, a Bluetooth transfer app that is built into Windows 7 and higher. We have written a blog post on how to use it.

Bluetooth has very low bandwidth, and even under ideal conditions it can take from 10 to 20 seconds to transfer a single photo. Larger files, such as music or video files can take much longer. If possible, using a USB cable or other wired means for transfer is always a better choice.

If the two devices are separated too far or if there is a lot of radio interference, the transfer rate can become even slower. While the specified range of the Plugable Bluetooth adapter is 10 meters, obstacles like walls, floors, doorways, and furniture can reduce the signal and slow it down. If the adapter is plugged into the back of a desktop computer or into a USB 3.0 port, it is possible that radio interference is degrading the signal. Check the items mentioned above in the Range is too short, or audio skips or lags section above.

If you don’t find a solution to your issue on this page, please contact us at We are always ready to help. You may also want to try our advanced troubleshooting steps.

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