This is the most reliable fix for users with pre-built computers. Often, the BCM2045A0 is used in HP or Lenovo desktops. Even if your PC manufacturer hasn't officially updated the driver for Windows 11, the Windows 10 driver usually works perfectly via compatibility mode.
If the manual assignment does not work, you can download manufacturer-specific drivers. Note that most official BCM2045A0 drivers were originally built for Windows 7 or 10, but they often still work on Windows 11 using .
Depending on your hardware, specialized drivers from your PC manufacturer might be required. Broadcom Broadcom BCM2045, v.6.1.0.4700, A01 - Dell
If you’ve recently upgraded to Windows 11 or performed a clean installation, only to find that your Bluetooth mouse, keyboard, or headphones won’t connect—or that the Bluetooth toggle is completely missing from Settings—you are not alone. The culprit is often a missing or incompatible driver for the chipset.