Boot Device not found after installing ubuntu 16 by complete erase of existing OS (windows 10)

[Rupmore]

Hi someone pls help me here ,
I have just installed Ubuntu 16.0.1 by complete erase of existing windows 10 on my EliteBook 840G1 , now i am getting error has Boot device not found , i saw some videos on youtube saying enabling and disabling legacy support but the thing is legacy support option itself is not there , i saw in some videos they have mentioned the option "secure boot configuration " in this we can find legacy support option but this "secure boot configuration " option also not there. I did all reseach but unble to find any solution pls help me.


Thanks a lot.

Rupesh

[personal information removed] 

[Rupmore]

This are the snaps .

Pls see attahced snps

[CherylG]

[Rupmore]

Hi dear,

I tried that also and UEFI native also , nothing worked out man

[David_J_W]

If legacy boot will not work then you have probably missed something out of your Ubuntu install. Make sure that you've installed a boot manager and set the active partition correctly.

The UEFI boot options will only work if you've installed Linux with UEFI booting in mind. If possible, it is best to install a system that boots UEFI Native with GPT, not least so that you can utilise Secure Boot if and when that is available on your chosen OS. Nevertheless, many people opt for legacy booting and MBR because it is familiar and more widely supported.

My experience with alternate OSes is primarily with FreeBSD, so I am not best placed to advise on installing a Linux distribution.

[Rupmore]

Thanks David,  

I am really newbie into this and don't knw about all these term but somehow i figured out to boot my system with ubuntu what i did is i went to Boot manger by F9 and then then i found some options there i went into \EFI\ubuntu\grubx64.efi and system booted successfully with ubuntu and then i went to Boot options by F10 and Add custom boot and in that i added that path  \EFI\ubuntu\grubx64.efi and restrated system and now its booting with ubuntu , however it stucking at purple window for 30 seconds intially at every boot up , but system booting up successfully. 

Thanks

[David_J_W]

If you're booting grubx64.efi then you probably want UEFI Native selected.

The 30 seconds is likely a timeout in grub to allow you to select alternative boot options such as booting single user for system maintenance purposes. I would investigate whether you can reduce that timeout to 5 seconds in the grub documentation.

[Rupmore]

Hi David,

Apericiate your suggestions.

Yes i had UEFI Native selected already ,

pls check snaps.

also check the Ubuntu Boot  video

https://drive.google.com/open?id=1remSmWp7326hwaLC4C8wtYhXxlADWUK3

-Rupesh