Black screen after failed upgrade

This is an issue my wife is having with her computer, but she has an Acer aspire 257 netbook, and when prompted to upgrade to Ubuntu 16.04 from 14.04, I clicked yes. The upgrade proceeded normally, and either because the battery ran out or some other reason, the machine crashed or powered off during the "cleaning up" stage of installation. When I tried to turn it back on, the screen was black, except for a login prompt that looked similar to the Terminal screen. I got past that, but the machine will still not boot. I have a 16.04 boot disk, so I used that and backed up her files and just tried to reinstall the whole system, but the reinstall recognized the version of 16.04 which is on there but won't boot. No matter which option I chose, it failed to remove the existing partition and erase the hard drive before starting the install. Now all you get when powering it up is a blank screen and a blinking cursor. Is there any way to get past this and just reinstall the OS?