I have a Windows 8 Ultrabook. I downloaded Ubuntu (release 12.04) and installed using the Windows installer (Wubi). On rebooting at the end of the installation, I get the Windows boot screen asking if I want to boot into Windows 8 or Ubuntu. I select Ubuntu, and I get an error message that says Ubuntu is missing a boot file or has errors. Please let me know how to fix, or if my procedure is incorrect.