The process of downloading the Gigabyte GA-Z77X-D3H (rev. 1.2) VIA USB 3.0 Driver 4.20 for Windows 8.1 driver should begin automatically after a few seconds. If this does not occur, click on one of the links below (we recommend downloading the Gigabyte GA-Z77X-D3H (rev. 1.2) VIA USB 3.0 Driver 4.20 for Windows 8.1 driver from the primary server - this is the manufacturer’s VIA official website). If the download still fails to run, check whether your anti-virus software is not blocking the connection to the manufacturer server of the Gigabyte GA-Z77X-D3H (rev. 1.2) VIA USB 3.0 Driver 4.20 for Windows 8.1 diver.