Hey guys,
Three days ago I've restarted my PC and suddenly all USB ports had stopped working. I have PS/2 Mouse and thats how I'm navigating through Windows. I have opened the Device Manager and saw that there's yellow exclamation mark right next to the USB xHCI Host Controller Driver. I've tried reinstalling, Disable/Enable used DriverEasy but nothing. Also I've uninstalled the last Win10 update. I will be really thankful if you could help me.
PC Specs:
MB: MSI Z270-A Pro
RAM: G. Skill Ripjaws DDR4-3200mhz 16GB
CPU: Intel Core i7-7700k
GPU: Asus ROG Strix GTX 1080

I seem to be having a run of bad luck with obscure and difficult to diagnose problems lately. This one has been particularly frustrating. Here's the story:
I built a PC with the following specs:
i7 4770k
ASRock Z87E-ITX
Corsair H80
Kingston HyperX Fury 16GB (2x8GB) DDR3 1866 RAM
Samsung 850 Pro 256GB SSD
WD Green 4TB
Silverstone Strider ST50F-ESG 500W Gold PSU
Corsair Graphite 380T Chassis
I installed Win7 Pro 64, then upgraded to Win10 Pro 64. Never had any issues with it, everything worked great. Sold it to a guy locally, and it worked fine for a few days, then randomly decided to stop recognizing all the USB ports (both 2.0 and 3.0). All the USB devices still work fine in BIOS (KB, Mouse, Flash Drive), so I figured it must be something on the software side.
I opened up device manager and I find that the 'USB xHCI Compliant Host Controller' is reporting that 'This device cannot start (Code 10).' Some googling shows that lots of other people have encountered this same issue, but concrete solutions are lacking. The only suggestion that seems to have worked for some people is to uninstall all the USB devices and let Windows reinstall them. I tried that to no avail, though in a single instance (dozens of attempts to repro failed) disabling the xHCI controller and then re-enabling it caused everything to suddenly detect and work again magically - until restart, then back to square one. I've looked around, but cannot find any drivers from either Asrock or Intel to try in lieu of the Win10 default (the most recent is for Win7 only and refuses to install in Win10). Trying to automatically update simply tells me I already have the best driver installed.
I went so far as to do a complete reset of Win10, which did not solve the problem. I then reinstalled Win7, and all the USB ports started working again using the default drivers - then I installed the aforementioned driver from the Asrock website, which caused the same 'device cannot start' error to start happening again. Uninstalling the driver makes everything work once more, though it leaves an unidentified item in device manager that doesn't seem to affect anything. Results are the same with the driver downloaded from Intel, which I'm pretty sure is the exact same driver.
I saved an image of the Win7 install with everything functional (IE, not using the asrock/intel driver) in case I need to go back to it, then went through the Win10 upgrade process once more. No joy, problem came back immediately.
Other notes:
* BIOS is updated to the latest version.
* Enabling the USB Compatibility Patch option in BIOS or disabling Legacy USB support does not solve the problem, but cause the BIOS to stop recognizing all USB devices (even with the UEFI Setup option that is supposed to retain USB support in BIOS), and then I have to do a CMOS clear to get back in.
TLDR: USB ports were working in fine in Win10, suddenly stopped and xHCI controller no longer starts. Can't find any updated or alternate Win10 drivers to use. USB ports are physically fine, everything works in BIOS and Win7 (as long as I don't change any of the Legacy Support or USB Compatibility options in BIOS, or install the updated driver available for Win7, which breaks it in the same way as Win10).
I'm hoping someone with a deeper understanding of all this stuff has heard of / encountered this issue before and can point me in the right direction.