You seem to be able to install OpenSUSE from Windows using Instlux. Does anyone here know what the result is for the Windows installation on the machine? Is it overwritten, or does Instlux work like Ubuntu's Wubi and leave the Windows installation intact? Does it add an item to the Windows bootloader? Does it change the MBR to boot with GRUB?
(Disclaimer: the answer below is based on Internet research.)
It is different from Wubi. Wubi creates a one-file filesystem inside Windows and you can boot into that as if you installed it into a different partition.
Using Instlux just eases the way OpenSUSE can be installed by starting the installer from within Windows.
It installs a small „kernel” within the Windows partition and by adding an entry to the Windows boot menu, it allows to boot into that, so you can continue a normal installation even without an installation media or tweaking BIOS settings.
After that point the installation process is the same as if you had booted from a CD-ROM. You create partitions beside the Windows partition on your hard disk.
You can see a few screenshots guiding through the process in this article.