Windows 11 Audio Devices Disappear After Boot – High Definition Audio Device Code 45

Hi No One,
Welcome to Microsoft Q&A forum. I'm happy to help.

The error code 45 in Device Manager indicates that this hardware device is not connected, that's why it was disabled and grayed out. You may read more about error codes here: Error codes in Device Manager in Windows - Microsoft Support.

Commonly, this means you probably have hardware issue, the device may appear again sometimes but it's not stable. This also may cause by power plan, driver issue, or system file corrupt.

Please troubleshoot by bellow suggestions:

• Switch power plan
  • Open Choose a power plan > switch to higher power plan.
• Driver issue
  • Use third-party application like DDU to completely remove Realtek drivers from your system.
  • It's recommended that you run DDU in Safe Mode.

    Disclaimer: Microsoft provides no assurances and/or warranties, implied or otherwise, and is not responsible for the information you receive from the third-party linked sites or any support related to technology.

• Scan your system
  • Run these commands in Command Prompt (Run as Administrator):

        DISM /Online /Cleanup-Image /RestoreHealth
        sfc /scannow
    

• Re-initiate devices
  • Unplug your computer from any power sources.
  • You may need to reset BIOS by removing CMOS battery for few minutes.

If all above suggestions cannot help bringing back your device, you probably have hardware problem.

I hope that above suggestions can help you resolve the issue.

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Hi,

Thank you for sharing your question. I understand how aggravating it is to lose your onboard audio with a Code 45 error after every cold boot, and I appreciate you reaching out for help.

It appears that Windows intermittently fails to detect your Realtek high-definition audio hardware, which leads to the “Currently, this hardware device is not connected” Code 45 message.

To resolve this, start by checking in Device Manager with View → Show hidden devices enabled; if High Definition Audio reappears, right-click and Uninstall device, then restart to let Windows reinstall the driver. If reinstalling triggers instability, obtain the latest OEM Realtek drivers directly from the Gigabyte B450 DS3H Wi‑Fi support site—generic or forced drivers may not be fully compatible.

Also, verify that onboard audio remains enabled in your BIOS, as it can reset after updates or boot—and then confirm in BIOS or UEFI that “HD Audio Controller” is still active.

If the problem persists after driver cleanup and BIOS checks, consider two additional steps: use pnputil to remove any stale driver packages from the Driver Store, and configure Windows Update to prevent automatic installation of problematic drivers.

I hope this helps.

Best Regards,

Noel