I was upgrading Day 0. Nobody knew what was going on, many people were affected. I do not know if they made a patch, if Asus updated their software or what- I keep USB acceleration from Fan Expert disabled just in case. My motherboard Z87 Deluxe did not have PS2 ports, so there was no way to access the computer- no mouse or keyboard would work from USB 2 or 3. Dead. So I did not install Fan Expert when I reinstalled Windows 8.1 from scratch at first, installed drivers and then installed Fan Expert and never used USB 3 accelerator. But I can not guaranty that this is what caused it- it was not official statement- just a tech told me. Just something to be aware of- it was disaster.