After apparently successful installation, my computer boots to the installer interface again
I used a live USB to install Ubuntu. Installation seemed to be successful, but when I restart my computer and choose Ubuntu to start, it goes to the installer interface again.
What's wrong?
Your system is probably booting to the USB first in the boot sequence.
Completely shut down. Then remove your USB from the system. That should allow you to boot to Ubuntu when you turn on the computer..