Currently, Ubiquity sometimes fails creating a correct Windows dualboot when:
- either it installs Ubuntu in EFI mode when Windows is installed in Legacy mode ( examples: Bug #908109 , Bug #959446 , Bug #956412
- or it installs Ubuntu in Legacy (not-EFI) mode when Windows is installed in EFI mode. ( example: http://ubuntuforums.org/showpost.php?p=12246811&postcount=6 )
In order to create a correct dualboot, Ubiquity should always install Ubuntu in the same mode as Windows.
This could be done by choosing between grub-efi and grub-pc based on the presence of an existing ESP when performing a side-by-side install, instead of whether the cd is booted in efi mode or not.
*************** WORKAROUND: using Boot-Repair to convert Ubuntu in the same mode as Windows.