Why I need to press F9 everytime I want to choose between two OS?

I have a dual boot in my laptop. I have Ubuntu and Windows installed. But whenever I boot my laptop, I have to press F9 to get the menu otherwise it will go to Windows directly without showing the menu. What is the issue here? How can I get the menu without pressing F9?

Solution 1:

Check if there's a boot option "OS boot manager" in your UEFI (I assume it's UEFI and not Legacy). If there is, give it highest boot priority.

Solution 2:

This sounds as if you have two disks in your machine, and are using the BIOS/EFI to switch between the boot disk. The is something not controlled by Ubuntu or Windows.

Best chance you have is to look into your BIOS/EFI Setup (Typically F1, F2, F10 or Esc) and look for an option that says "Always show boot menu". That option does not always exist.

You can change the boot order in the BIOS/EFI, so that it boots straight to Ubuntu instead.

Finally, you can install GRUB on the boot disk and it will give you a menu to choose. Most likely, this is already the case if you set your boot disk to your Ubuntu disk.

(Edit: Based on discussion in comments)

The boot order often must be changed with the + and - keys or F5 and F6 within the appropriate menu of your BIOS/EFI.