I have a machine that came with 12.04 LTS pre-installed. After working seamlessly, it sat unused for a bit and now will not boot properly. I've searched for fixes, but none has worked. I'd like to just do a "clean install" of 12.04.3.
I have created a bootable DVD. Once I'm in the boot menu and boot from the DVD, is there anything else I need to do? Will the installer "overwrite" what is already installed or do I need to remove the old OS first? I won't end up with two partitions, one with the old broken OS and one with the newly installed one, will I?
Please use as simple as language as possible when answering.