After turning on my PC the other day, I got a screen message saying my hard drive was about to fail. I bought a new hard drive and installed it then turned on the computer, went to the boot menu and told it to boot from the USB (which contained a copy of Windows 10). Everything went perfectly: Windows 10 installed itself, I installed some programs and everything was working perfectly until I tried to restart the computer – it just wouldn't boot up. I wondered if it was still trying to boot from the USB which I had already removed. I went back to the boot menu and it was still set to boot from this USB. I've tried all the other settings in the boot menu but it just won't boot up. I get to the screen showing the blue window and the little dots running round in a circle but it will go no further. Can anybody help?