Depending on the exact year of your A1278, you will need one of two packs:
If you have wasted hours with no solution, wipe Windows and start fresh. Apple Macbook Pro A1278 Audio Driver Windows 10
After a reboot, the audio hardware is recognized, and the headphone jack and internal speakers function correctly—though often without the automatic switching between speakers and headphones that macOS handles seamlessly. Depending on the exact year of your A1278,
Sometimes, it is not the driver. The A1278 is known for a specific hardware fault: the connecting the logic board to the I/O board (where the headphone jack sits) can fray. the audio hardware is recognized