I was installing Ubuntu on my brother's laptop, but then it failed. It said something about grub failing to install. After that I tried to boot back to windows 10, but it failed. I booted to Ubuntu live and checked if something is missing on the main hard drive. I checked and the files is still there. How do I boot back to Windows and what is the problem with installing Ubuntu? Thank you in advance :)
PS. When I tried to boot to the usb before installing I saw "Windows Boot Manager" and after failing, it was gone. Does it have something to do with the problem?