Jari
jarkky, Great to see you made it over to the new forum. 
Could you please run a Boot Repair using your Zorin Media disk?
https://help.ubuntu.com/community/RecoveringUbuntuAfterInstallingWindows
It didn’t help to run the “Boot Repair” in the USB-booted ZorinOS15.2:
Could you please boot into Windows and open a command prompt and enter the following:
bcdedit /set {bootmgr} path \EFI\ubuntu\grubx64.efi
The new HP F.10 bios does not let select the "ubuntu" (even it is visible in the selection box):
Even I used this BCDedit command, that still could boot only windows10.
Note that this is "UEFI", not "EFI".
The laptop already had Windows10Pro from the purchase and earlier bios version case I can use the ubuntu (or grub) bootloader.
I should find how to select the ubuntu boot loader in the BIOS.
Also if I should switch to the EFI mode, then I could not find how.
Yes, that is confusing... But the command is efi when you have uefi. I even triple checked that before posting it.
We know Zorin is there... Just need to get at it.
What I have found in searching:
I got it working.
The problem is just to make this BIOS setup.
The selection of ubuntu (instead of windows) must be terminated by F10 instead of ENTER.
The enter can not validate the selection of the BIOS bootable OS.
So in the menu where is “windows”/“ubuntu”, by using keys F5/F6 set the “ubuntu” as the 1st and then terminate selection by pressing F10.
This seemed to fix the problem.
I was going to say, from your screenshot you have Secure Boot [Enabled].
I believe Zorin installation advice from Swarf and Co suggest this should be Disabled.
I am a relative newbie, so apology if that is a red herring.
I think you would have to delete if, for example, the system (BIOS) treats DVD-RW’s and USB sticks as Legacy boot devices - on newer machines (like mine) I have seen two entries - EFI and Legacy! When installing Linuxes now you have to provide an EFI partition formatted to FAT32 of 50 Megabytes (sometimes called ESP:
https://www.diskpart.com/articles/efi-system-partition-4348.html - states 100 Mb.
Provided Windows 10 is not on GPT partition (usually for SSD) then NeoSmart EasyBCD would solve the issue.
And @jarkky - remember the old BIOS key is still the new BIOS key - F10 has always been ‘Save and Exit’ 
The only time i have seen that requires a larger uefi partition for efi boot is popos.. for some reason they require 500mb.
While we're on the subject, last time i deleted an efi partition it wiped all my ext4 partitions.... any way to delete these without wiping the drive, now that the other efi sees and uses from the ext4 partitions?
