I have an old pc dual boot with windows 7/ubuntu 14.04. I tried to change ubuntu with xubuntu 20.04 booting the latter from the cd-drive. The installation was doing fine but at some point when it was updating grub the power failed. When i open the pc, it prompts to grub 2.04 minimal BASH-like. Then i tried booting again from the cd-drive to reinstall xubuntu but it prompts again to grub like it is booting from the HDD. I have tried the cd in another pc and it works fine. I have set from the bios (no UEFI availiable it is rather old) the booting order to the CD-drive first but it didnt change anything. I tried to boot windows and super-grub-disk with the same result. Any suggestions? I would greatly appreciate it if you have any suggestions to keep in mind that i am new to linux.
My pc specs are the following motherboard-->gigabyte GA-965P-DS3 cpu-->core 2 duo e6600