Is it possible to having installed Windows 10 and Ubuntu reformat 100MB Efi partition and 2MB BIOS boot partition to make everything grub/efi work? Also is it possible to remove or see the content of /dev/sda where is grub installed? I have such situation, have all partitions with installed Windows and Ubuntu + Windows recovery and Windows restore partitions but bios stopped to see the hard drive in bios boot options (It detects the hard drive as hardware with all model info, etc) and only see in boot options DVD and aditional USB if attached.
I have all set on Efi boot partition and have issues with make it work so addidtionally created 2 MB of legacy BIOS boot partition but not sure what should be placed there? Grub2 i386 image? So...there is grub installed on /dev/sda, Efi partition with efi grub and boot/windows/ubuntu efi files and bios boot partition empty...what can I do to try to make the bios see again hard drive filesystem to choose or just boot options based on hard drive? grub.cfg seems to be properly configured