I had trouble installing Windows 7 from USB on an Asrock Q1900M motherboard. It was the most difficult time I’ve had in years. Creating a bootable USB stick from my Win7 DVD went flawlessly, and the Asrock booted off it just fine by hitting F11 to pull up the boot menu, but then Windows prompted me for a driver, and when I navigated to the drivers directory that Asrock provided, none of the drivers would load. The mouse didn’t work either, and the only reason the keyboard worked was because I still use PS/2 keyboards.
The solution was to go into the UEFI, dive into the USB configuration, and disable USB 3.0. After I did that, Windows could see the USB drive and other USB devices just fine. This issue is likely to get more common as time goes on.
And yes, I’m building a new machine and putting Windows 7 on it. I’ll upgrade it to Windows 10 in a few months, but I’ll keep using Win7 until more of the problems in Win10 are shaken out.
For what it’s worth, the Asrock Q1900M is a nice board. It’s very low-end, but the Celeron J1900 SoC on it keeps pace with the early Intel Core 2 CPUs while consuming 27-36 watts of power depending on system load. For web browsing and running productivity software, it’s fine, especially when you give it plenty of memory and an SSD. If you were to power it with an external power supply, you could build a dead-silent system with it.