Nvidia driver 384 ran well on Ubuntu 17.04 and 17.10. I switched to Ubuntu 18.04 (clean fresh install) and installed nvidia-driver-396 following this great answer

Then I installed cuda toolkit 9.2 using .run file. It failed to install with and without choosing to install nvidia driver along with it. Rebooted and tried again, then cuda was installed succesfully. But nvidia isn't running.

$ nvidia-settings
ERROR: NVIDIA driver is not loaded


ERROR: Unable to load info from any available system


$ nvidia-smi
NVIDIA-SMI has failed because it couldn't communicate with the NVIDIA driver. Make sure that the latest NVIDIA driver is installed and running.

$ lspci -v | grep VGA
00:02.0 VGA compatible controller: Intel Corporation HD Graphics 5500 (rev 09) (prog-if 00 [VGA controller])

What I have tried so far:

1. Uninstalled nvidia (nvidia-uninstall) Successful but with warning: "Some symlinks could not be removed. The I removed cuda with rm -rf /usr/local/cuda* and installed nvidia-driver-396 but still the same error

2. Removed nvidia-396, installed 396 from nvidia's website (.run file). It started with a warning "Distribution provided pre-script failed". I proceeded and installation was successful. It also added nouveau to blacklist automatically. Still same result as 1.

3. Uninstalled previous one, removed blacklist entry, installed nvidia-390 Still same result

4. Uninstalled previous one, installed it from "Additional drivers" from GUI. No change.

5. Went to console mode. Stopped gdm. Then installed 396. No change. Installed 390 likewise. No change.

6. Tried using xorg-edgers ppa (Yes its is said they are same as graphics-drivers ppa but I am desperate now) Unmet dependency problems. So reverted to removed everything.

7. Uninstalled everything, went to recovery mode then installed nvidia-driver-390. No luck.

8. I felt nvidia driver from official website made some irrevesible changes. So tried installing it again so that I can uninstall it properly from recovery mode as suggested in the great answer using --unistall option. But now it fails to install. Error message says nouveau is running despite being blacklisted. I removed the blacklist entry later

I have Intel i5 with Intel HD graphics along with Nvidia GeForce 940M. Yes nvidia-prime was installed. Dual booted with Windows 10, Secure Boot is disabled

During all these steps, once I was able to start the nvidia x server app, though the nvidia-smi gave the same error. Once there was a resolution issue when cuda ran nvidia-xconfig. I removed the xorg.conf to fix it. Right now my pc has nouveau running, no other drivers installed, no blacklisting nvidia, no xorg.conf.

Can someone help. I don't see any reason why it should not work. nvidia driver 390.12 is reported to work well with kernel 4.15 but still it is not working on mine.

I checked by ls -al in my home directory but I don't see .bashrc file in my home directory. Ubuntu 18.04 release notes does not mention anything about this. I installed it without formatting previous /home partition after deleting files like .bash_, .local, .gnome, etc. I am able to use the pc like normal but where is the bashrc file now? Isn't it supposed to be recreated automatically?

Ubuntu Gnome 17.04 requests to know my location after every boot. I never experienced such thing with Linux distros before. Can anyone explain why this is so?

TL;DR

It's not possible to add Grub boot entry in Windows Boot Manager.
But something similar can be achieved using a third party boot manager like Rod Smith's rEFInd. Installation steps are well explained in this gist
But Acer laptops (tested on 3 Acers) apparently forgets boot entries and only windows boot manager loads despite refind/grub is present in ESP.
Acer laptop's UEFI menu has two hidden settings that become available only when you set a password for the UEFI menu. You can then mark any third party boot manager as TRUSTED without signing the boot manager with RSA key (as shown in the gist and many other places). You can disable secure boot too if a password is set. If UEFI is enabled, only TRUSTED boot managers are loaded by UEFI and all others are ignored because of which only windows boots and we incorrectly think UEFI forgets boot entries.
An alternative is to disable UEFI but why lower the security ourselves when there is a solution?

The long story

My old laptop used MBR scheme and I was able to install grub on Ubuntu's partition (not on MBR) and then added a boot entry for grub in Windows boot manager. This enabled me to keep windows boot manager as well as grub.

My new laptop came with Windows 10 pre-installed with UEFI. I installed Ubuntu Gnome 17.04 with the following partitioning-

/boot ext4 1GB
/ (root) ext4 25GB
/home ext4 400GB

I thought this will install grub on /boot (It might have, I don't know)

Installation was successful

I rebooted into Windows and ran EasyBCD 2.3 (latest) to add a boot entry for grub in windows boot manager. But that option was greyed out. EasyBCD say that because I have secure boot enabled some features are not supported. I can see option for adding a boot entry for another Windows OS but the same options are greyed out for linux OSes.

I want to keep both Windows boot manager and GRUB but on separate partitions so that I can goto GRUB from Windows boot manager as I did in my old laptop.

Why?

1. I plan to upgrade to 18.04 LTS and/or update OS shipped kernel to mainline kernel
2. The GRUB screen is quite scary for my siblings who also use my laptop

Update 1: UEFI boot menu (from F12 key) shows only one entry which is for Windows. If grub is present in /boot or /EFI/Ubuntu it should show up in boot menu. I have tried reinstalling without a /boot partition but still no luck.

Edit: It's Acer V3-574G-54VY running on i5-5200U. System Information shows-

BIOS Version : Insyde Corp V1.35, 30-11-2015
BIOS Mode : UEFI

It came with UEFI firmware ("BIOS Version" in System Information) V1.1. I updated it to V1.35 two months ago.

Update 2: I followed @RodSmith 's blog and fixed grub not being shown in UEFI boot menu using efibootmgr. I am now using GRUB (via shim with SecureBoot Enabled) as the default bootloader. But my question is still unanswered. How do I add Grub/Ubuntu bootloader entry to Windows Boot Manager? Does Windows Boot Manager support such configuration? I am in doubt now because when Windows Boot Manager was default, it deleted GRUB boot entry in EFI at every boot.

Another thing worth noting, I did not disable fast startup in Windows probably because of it Ubuntu installer could not install GRUB (or it installed grub but Windows Boot Manager that loaded first because of fast startup, removed it at boot)

Update 3: I rebooted to Windows and it deleted GRUB boot entry and made itself default again. Now I m back to where I was.

Update 4: I configured boot order from Windows bcdedit and now the boot order persists across boots. I had to disable secure boot. Secure Boot toggle is ungreyed after setting Supervisor password in UEFI. I have to enter that password everytime I goto UEFI menu. This probably implies it would be impossible for any app to modify UEFI settings when Secure Boot is disabled. I don't think my UEFI is buggy, it's quite advanced and more secure than other vendors