Dual Boot problem

[alvinrr]

I installed for dual boot Ubuntu 18.04 on my Windows 10 PC. and when my PC needs to restart, it booted straight to Windows 10 and did not show the grub menu.
Now I typed this in command prompt "bcdedit /set "{bootmgr}" path \EFI\ubuntu\grubx64.efi" and restarted the PC. The problem is it is now boots straight to Ubuntu without the grub, and when I used grub customizer, it doesn't show the windows boot manager.

In the boot manager in UEFI, when I click windows, it boots to Ubuntu.

sorry for my English..
Please help.

[slickymaster]

Thread moved to Installation & Upgrades.

[CelticWarrior]

Do not complicate things (yet) with additional software and doing things you don't know. Typically doing that makes things worse.

Just boot Ubuntu again, run
sudo update-grub and reboot. What happens now?

[alvinrr]

same thing happened, I have the grub now, but it shows no windows OS.

it only shows

Ubuntu
additional ubuntu ...
mem test ...
mem test ,......

[CelticWarrior]

That means you have Windows and Ubuntu installed in different modes -or- Windows is semi-hibernated due to Fast Startup...

Now... Please open UEFI settings and check if you can select "Windows bootloader..." instead of "Ubuntu" (in the Boot menu). If you can then it should boot Windows directly. If so, disable Fast Startup. Shutdown. Boot again and change the boot order back to "Ubuntu" and if necessary repeat the command in the previous post.

[alvinrr]

I already disabled fast startup when I installed Ubuntu.
about selecting windows boot loader, when I clicked windiws, it boots to Ubuntu.

Just booted up, and nothing happens.

[CelticWarrior]

Fast Startup is a Windows feature, do not confuse it with Fast Boot, a firmware (UEFI) setting...

So, right now, you need to repair Windows because, apparently, the command you tried first screwed the Windows bootloader (that's what happens when we mess with things we don't understand).

Please boot the Windows installation media of the same Windows version and follow instructions for repairing. Once your Windows is booting directly again, all you need to do is change the boot order back to Ubuntu and run the command.

[Impavidus]

I already disabled fast startup when I installed Ubuntu.
That doesn't mean a lot. Windows can automatically turn it back on during updates and doesn't inform the user about it.