I've been trying to install the Intel USB 3.0 eXtensible Host Controller Driver (version 18.104.22.168 as supplied by the Asus web site) but it balks when it gets to the PCI bus. At this point the entire system freezes for about 30 seconds and then a generic message is returned saying the install failed and some devices were not installed. If I try to install the PCI bus driver manually via the Device Manager (updating from the stock Microsoft driver and pointing it to the directory where the Intel USB3 drivers reside) It fails saying "The parameter is incorrect". Something has occurred in this process though, because the Device Manager is now listing the driver as Intel, version 22.214.171.124. Rebooting at this stage causes a BSOD while loading windows, requiring a repair boot and System Restore to recover.
Searching the Intel web site for the same drivers (in case the Asus copy is corrupt) only returns drivers for Series 7 or Series 8 chipsets, with no specific mention of Series 9 (I have Z97).
Why am I trying to do this? All my chipset-controlled USB3 ports (including the motherboard headers) are only operating as USB2. I have two ports fed by an ASMedia controller and they seem OK, it's just the Intel ones. this means I can't get my Akasa card reader to work, as it uses the motherboard headers.
I've tried reinstalling the chipset drivers (also downloaded from the Asus web site) to no avail. Any attempt to dislodge the Microsoft driver in favour of the Intel one results in boot failure.
The motherboard is an Asus Z97-PRO(Wi-Fi ac). I'm sorry I can't provide any more technical information at present (working nights and my PC is about seventy miles away) but if you tell me what you need I'll be back in about twelve hours...
I have half an answer: I went into the BIOS and changed Intel xHCI Mode to Enabled instead of Smart Auto, and all my USB devices appear to be operating correctly now. The driver still fails to fully install though, failing at the PCI bus again (although without the freeze this time). Here's a screenshot of the error message, for what it's worth.
At least now I know my motherboard is not faulty, and everything works. Partially installed drivers always worry me though, in case they cause problems further down the line...