yup, i've already changed the graphic set-up with the setup.exe.. its just weird, that setting the sprite and texture to low would prevent ragnarok from running.. ^^ already got it to work, thanks heero! you're the best ^^ thanks for all your hard work.. and for those who may experience this problem, just change back your sprite and texture setting in the setup.exe.. KUDOS to you guys!

i dont know if its just mine, i also tried it on my brother's laptop, and it also wouldn't run.. just weird ^^ well all solved, so no problem on my part.. works the way it should.. though i have to refrain from closing my client with LOW sprite and LOW texture..
P.s. if you have time to reproduce my error, basically here's what happens..
run ragnarok -> when online, change video configuration (sprite and texture setting) to its lowest possible setting -> alt + F4 = prevent my ragnarok from running..
its not of a big problem, but some people may experience it. maybe it'll help them solve their problem^^