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How to fix Bluetooth missing or disappeared in Windows (Code 43)

Error code: BT-ERR-43

What this error means

The Bluetooth toggle is missing or greyed out in Settings and Quick settings. In Device Manager the adapter may show a yellow warning, often with Code 43 (Windows stopped the device because it reported problems). Microsoft says this is typically caused by problems with drivers or firmware from the PC maker. A full shutdown, a driver update and the PC maker's optional updates or BIOS update fix most cases.

Updated

Applies to
Windows 11 and Windows 10
Difficulty
Beginner
Before changes
Low; BIOS updates need care

Reviewed by Matyáš Rada · Documentation checked: 2026-10-31 · Checked against Microsoft's Bluetooth and Device Manager error code articles; not tested on every PC.

Before you begin

Check that your PC has Bluetooth at all: many desktops do not, and Microsoft's first step is to check the product specifications. If Windows cannot start, see the startup guide.

Work through these checks

0 of 7 complete
01Shut down fully, not restart

Microsoft's first solution is a full shutdown, which completely powers off the Bluetooth hardware.

  1. Hold Shift and select Start > Power > Shut down.
  2. Wait one minute, then turn the PC on.
  3. On a desktop, you can also switch off the power supply during that minute.
What to expect

The Bluetooth toggle is back.

If it does not help

If it is still missing, continue with step 2.

Browse related errors
02Check airplane mode and the Bluetooth switch

Airplane mode and hardware switches turn the Bluetooth radio off.

  1. Press Windows + A and make sure Airplane mode is off.
  2. On a laptop, check for a physical wireless switch or a function key with a Bluetooth or airplane symbol.
What to expect

Bluetooth can be turned on.

If it does not help

If the toggle is still missing, update the driver in step 3.

Browse related errors
03Update the Bluetooth driver

Microsoft says this problem is typically caused by drivers or firmware.

  1. Right-click Start > Device Manager and expand Bluetooth (if the category is missing, look under Other devices or Network adapters).
  2. Right-click the adapter (its name may include Bluetooth or Radio) > Update driver > Search automatically for drivers, and restart if asked.
  3. Or install the Bluetooth driver for your exact model from your PC maker's support page.
What to expect

The adapter works and Bluetooth appears in Settings.

If it does not help

If the adapter shows Code 43, continue with steps 4 and 5.

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04Install optional updates and BIOS updates

Microsoft recommends optional updates and, if none are offered, BIOS or firmware updates from the PC maker.

  1. Open Settings > Windows Update > Advanced options > Optional updates, tick available driver updates and select Download & install, then restart.
  2. If nothing is offered, check your PC maker's support page for BIOS/UEFI and firmware updates.

Do not switch off the PC during a BIOS update.

What to expect

Bluetooth works after the updates.

If it does not help

On many laptops, Bluetooth and Wi-Fi share one card; updating the Wi-Fi driver from the same maker can also help.

Browse related errors
05Reinstall the adapter

For Code 43, Microsoft's recommended resolution is to uninstall and reinstall the device.

  1. In Device Manager, right-click the Bluetooth adapter > Uninstall device > Uninstall.
  2. Shut down, wait, and turn the PC on; Windows reinstalls the adapter.
  3. If it does not reappear, click Action > Scan for hardware changes.
What to expect

The adapter works without a warning sign.

If it does not help

If Code 43 returns, run the troubleshooter in step 6.

Browse related errors
06Run the Bluetooth troubleshooter

The troubleshooter checks the adapter and services automatically.

  1. On Windows 11, run the Bluetooth troubleshooter in the Get Help app.
  2. Apply the fixes it suggests and restart.
What to expect

Bluetooth works again.

If it does not help

If nothing helps, check the hardware in step 7.

Browse related errors
07Check the adapter hardware

If drivers and firmware are current, the adapter itself may be faulty or disconnected.

  1. On a desktop with a Bluetooth card, check that it is seated and that any antenna and internal USB header cable are connected.
  2. As a test or a replacement, use a USB Bluetooth adapter.
  3. Contact the PC maker if the built-in adapter stays in an error state.

Switch off and unplug the PC before opening it.

What to expect

You know whether the built-in adapter is faulty.

If it does not help

Microsoft recommends contacting the PC maker for driver or firmware problems they provide.

Browse related errors

Possible causes

  • The Bluetooth adapter is in an error state until a full shutdown
  • An outdated or damaged Bluetooth driver
  • Outdated BIOS/UEFI or firmware from the PC maker
  • Airplane mode or a hardware switch turning Bluetooth off
  • A faulty or disconnected Bluetooth adapter

Useful Windows tools

These commands open Windows tools. Review changes before applying them.

devmgmt.msc

Sources & further reading