Fix This device is not working properly because Windows cannot load the drivers required for this device. (Code 31) Network Adapter issue.

Unable to manually update the driver, online searches suggest this is a known problem but only fixes appear to be to purchase a driver update/repair program. Is there a free solution to this problem?

These aren't like your chipset or graphics drivers where you can (and should) update them yourself, but fortunately, Windows has a built-in scan tool to help fix file system and Windows driver errors.