Quote Originally Posted by coffeecat View Post
You mention Ubuntu and Windows machines suggesting they are different machines. Am I correct?
Wow! I don't know when and why I made the assumption that it is the same machine dual booting Windows and Ubuntu.

I re-read the first post and they are clearly two different machines. That's a really strong point, and coffeecat has already given the best suggestion to test external factors.

PS:
@dani.rab
If the machine is Ubuntu only, you'll have to press 'Shift' or 'Esc' key during bootup to get the grub boot menu.