I had 2 Windows 7 64-bit and Ubuntu17.04 installed on my Lenovo Y50-70 laptop. I decided to reinstall them. I formatted all disks and installed Windows 7, leaving about 50GB free space for Ubuntu 17.10. I installed Ubuntu (I chose to install with Windows 7 option), rebooted and got stuck with this black screen:
It didn't disappear, so I decided to push the power button. Then it rebooted and showed this message:
Then GRUB turned on and there was no option to run Windows 7, only Ubuntu. I tried to reinstall Windows 7, but every time I got the message that there is no driver (I started the setup, changed the USB port, etc. but nothing helped). Then I reinstalled Ubuntu and now every time I start the computer I have messages like in the second image. I tried to set the BIOS preferences to default, or just change the EFI mode for USB boot, but for some reason the settings aren't saved. When I try to run Windows, it gives me the second error message screen, but Ubuntu 16.04 is installing without any problems, except one, that at the end of the installation I'm getting the first error message screen.