I know this is a common problem and some solutions are mentioned on this platform and the Internet, but I'm still not getting it. First of all, I installed Ubuntu 20.04 on a USB stick, so I don't lose my Windows 10 or cause it any issue. However, when I rebooted the computer (ASUS), I got this message:
Minimal BASH like line editing is supported. For the first word, TAB lists possible command completions. anywhere else TAB lists possible device or file completions. grub>
I freaked out of course. Nonetheless, I found one solution online, which is to enter "exit." Indeed, I could see a black screen with a few options, including Ubuntu and Windows boot manager (...).
This is how I have been choosing which system to start. I need to enter exit every time. This doesn't sound normal. How can I get rid of this message? If I need to use the Terminal on Ubuntu, please explain to me what each line means. I'm still learning this. I never thought this would happen because I assumed using USB won't affect the computer at all, but even if the USB isn't plugged in, I still see the message.
I did try sudo grub-install from the terminal, but the problem persists.