A specific quirk of the A1278 in Windows is the Red Light inside the headphone jack.
Once downloaded, you will have a file named BootCamp5.1.5621.exe. Do not run the full installer immediately – it might fail on Windows 10.
Navigate to the audio driver:
Install manually via Device Manager:
Reboot your MacBook Pro.
Best for: Users doing a fresh install.
Because Apple no longer supports the A1278 for Windows 10, the community has risen. Here are verified sources: Apple Macbook Pro A1278 Audio Driver Windows 10
Warning: Never download drivers from random "driver finder" websites offering paid fixes. They are malware. The only safe sources are Apple’s official servers (swcdn.apple.com) and GitHub repos with visible source code.
For later A1278 models, the Realtek High Definition Audio driver is required.
Driver name:
Cirrus Logic CS4206B (Apple-specific variant) A specific quirk of the A1278 in Windows
Source:
Boot Camp Support Software 5.1.5621 (or 5.1.5769) for Windows 8.1/10
Driver file path inside Boot Camp package:
BootCamp\Drivers\Audio\Realtek\
Manual install method (if auto fails):
Driver version that is known stable:
6.0.1.7542 (dated 2013–2015 range)