What exactly do you mean by "from windows 8"? Is this a wubi install trying to install Ubuntu as a program inside windows? If so, that isn't expected to work. See the Ubuntu wubi site below:
If you want to install Ubuntu on its own partition, you must first burn it as an image to a DVD or use software designed for the purpose to create a bootable flash drive. If windows 8 came pre-installed, it is most likely using UEFI to boot which adds another layer of complexity to the situation. Post more details on exactly what you have tried and how.