Originally from this HP forum thread, but I’m backing it up for a video in the coming few days.
You can grab the file here: AMD ASD WB64A.
Extract it somewhere on your computer. Right click on the “Unknown Device” entries on Device Manager, choose Properties, choose Update Driver… from the Driver tab, don’t let it search online (say you have a disk). Then selected “Show all devices”, Have Disk…, point it to the folder extracted from the archive, select the item that it shows which should be something like AS4 Device or AMD AS4 Device.
Hit OK, follow the prompts. Rinse and repeat. Note that there will be one that does not have a driver, that is a specific Valve ACPI device and there’s no drivers for it. It should not affect operation though.