Hello, thank you for reaching out to Microsoft Q&A.
Are you able to pair any other Bluetooth devices with your Computer? Such as your Mobile device?
Ensure the headphones are in pairing mode. If Windows is still not able to detect your headphones,
1
Run the Bluetooth Troubleshooter.
Go to Start > Settings > System > Troubleshoot > Other troubleshooters > Bluetooth and click Run.
Once the troubleshooter is finished running, restart your computer and pair your headphones.
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2
Reinstall Bluetooth drivers.
Open Device Manager.
Expand the arrow next to Bluetooth.
Right-click your generic Bluetooth driver, Intel (R) or Realtek, select Uninstall device, select the Attempt to remove the driver software for this device check box, and click Uninstall.
Once uninstalled, restart your computer and pair your headphones.
Let me know if you still need more help.