@Bernadette: If I would have same situation again, I think I would:
1 - Ctrl-Alt-F3/2 at login prompt 2 - sudo apt purge nvidia* 3 - sudo apt install nvidia-390 4 - sudo prime-select intel 5 - sudo nvidia-xconfig 6 - sudo nano /etc/X11/xorg.conf 7 - .. and replace with contents of #117 8 - sudo nano /etc/default/grub 9 - .. GRUB_CMDLINE_LINUX_DEFAULT="'quiet splash acpi_osi=Linux acpi_osi=! acpi_osi=Windows 2009' nouveau.runpm=0" 10- sudo update-grub 11 - sudo reboot 12 - login... 13 - and start praying...
@Bernadette: If I would have same situation again, I think I would:
1 - Ctrl-Alt-F3/2 at login prompt LINUX_DEFAULT= "'quiet splash acpi_osi=Linux acpi_osi=! acpi_osi=Windows 2009' nouveau.runpm=0"
2 - sudo apt purge nvidia*
3 - sudo apt install nvidia-390
4 - sudo prime-select intel
5 - sudo nvidia-xconfig
6 - sudo nano /etc/X11/xorg.conf
7 - .. and replace with contents of #117
8 - sudo nano /etc/default/grub
9 - .. GRUB_CMDLINE_
10- sudo update-grub
11 - sudo reboot
12 - login...
13 - and start praying...