Is a laptop, no? Any time you see "Intel" for the graphics, FF14 is going to have issue. The fact that you can run it at all is more than most people ever get, full screen or windowed. As much as I hate to say it, if that's all you have in it, I would take what you have and roll with it, and hope that windowed mode doesn't break as they update the game.

IF you have the nVidia Optimus thingy in there as well (and you might, depending on the exact model of the laptop?) then there should be some settings that allow you to force it to use the nVidia chip over the Intel. There's a few posts in the forums about it you can search for, or alternately see if someone else pops up with details, as I don't personally have experience with them.