Have a specific issue with your H81H3-AM? Open Device Manager, find the problem device, note the Hardware ID, and search that string. That is the most direct path to a solution.
Always prefer the motherboard vendor’s recommended driver for that exact model and BIOS revision if you want maximum compatibility. Acer H81h3-am Drivers
This is critical. Without it, PCIe lanes, SATA, and USB controllers may not enumerate correctly. Have a specific issue with your H81H3-AM