Entire computer is broken after installing ubuntu 16.04

I had ubuntu 17.04, and I had wifi problems with it, so I reinstalled 16.04, and now whenever I boot my computer, I get a boot screen that says

boot menu App Menu
1. ubuntu Setup
2. USB HDD: Diagnostic Splash
3. Windows Boot Manager

If I enter anything, it just reloads to this screen.

I can't boot into windows or ubuntu. Please Help as I need to go to work, and this computer is what I use to work.

1 Answer

Create a live Ubuntu flash drive, and use boot-repair. You can get more in-depth instructions here.

Basically, you have to run

sudo add-apt-repository ppa:yannubuntu/boot-repair
sudo apt update
sudo apt install -y boot-repair && boot-repair

then follow the instructions it gives you after pressing Recommended Repair.