After installing ubuntu 20.04 on a new differnt drive from my Windows 10, I restored my linux / from previous install as explained here. Before restoring I was able to go from Linux to Windows by pressing F12 before OS boot up.
Beginning of my problem: I didn't reinstall GRUB after restore, and restarted. Grub seen at startup had previous PC's details. Several errors came, and I turned to boot-repair - whose details are here.
After using boot-repair's recommended fix, my Dell laptop froze on ubuntu screen.
My question is.. how to get ubuntu running without a clean new install. A clean install is possible only after removing Windows m2 ssd which is enabled with Intel RST. That's how I installed Ubuntu in the first place.
Windows shouldn't be affected.
Here are some outputs taken from the live USB
sda 8:0 0 447.1G 0 disk ├─sda1 8:1 0 512M 0 part └─sda2 8:2 0 446.6G 0 part sdb 8:16 1 7.5G 0 disk └─sdb1 8:17 1 7.5G 0 part /cdrom
/dev/sda1: UUID="F00D-05A3" TYPE="vfat" PARTLABEL="EFI System Partition" PARTUUID="107a1476-213a-41d6-bd31-920a7abdf993" /dev/sda2: UUID="7733f1fe-fde6-4142-8f42-c26187052366" TYPE="ext4" PARTUUID="91f222f3-f67f-4ded-98f4-adad420c42cd" /dev/sdb1: LABEL="UBUNTU 20_0" UUID="A4FD-88A2" TYPE="vfat" PARTUUID="03d3e14d-01"
Note that Windows is not seen by Ubuntu which I suspect to be the source of freezing. Boot-repair generated a grub config file with hd0,gpt2 as sda2 (current linux root) while grub rescue shows hd1,gpt2 to be the real root. But I am not sure.
Please give advice.