Windows loads directly without showing the grub menu [duplicate]

I have HP Pavilion 15 Notebook PC preinstalled with Windows 8. I installed ubuntu 14.04 (dual boot) , followed by an upgrade to Ubuntu 15.04. I also upgraded to Windows 10. Recently, due to some reasons, Windows OS directly loads without showing me the Grub menu and letting me select the OS I want to load. I have to press Esc key followed by F9 to see the boot options and select the OS from there. Is there any solution to this problem, without reinstalling Ubuntu?

I want to select the OS I want to load directly from the Grub Menu which should show up on system startup.

None of the previous answers related to this question solved my problem.

In your Windows OS, go to Change advanced startup options. Follow these steps:

1. Click the Cortana icon and type advanced.
2. Click on Advanced startup.
3. Click on Restart now in the next menu.
4. In the following menu click on Troubleshoot.
5. Now click on advanced options.
6. Select UEFI Firmware Settings by clicking on it.
7. Now restart your computer.
8. Your system will now boot into BIOS. Using the arrow keys go to the Boot section.
9. Make sure that you have UEFI selected in Boot Mode.
10. Scroll down to the EFI section below which is your boot order.
11. Here set your Ubuntu OS at the top and your Windows boot manager below Ubuntu.

Note: If you are likely to use USB device to boot from then this is a good time to enable USB Boot. You would also want to set USB Boot at the top of your boot order followed by Ubuntu then Windows.

12. Exit saving changes.

Try booting and you should now have a choice to what you want to boot.

This is because you installed Windws 10 after installing Ubuntu. Windows boot overrided Grub. You can fix it by typing these commands in the terminal

sudo add-apt-repository ppa:yannubuntu/boot-repair
sudo apt-get update
sudo apt-get install -y boot-repair && boot-repair

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