Coming back after years, I've faced the same issue.
This http://forum.ratemyserver.net/ro-client-support/problems-with-the-size-of-the-window/ somehow seems like a workaround.
Requires some registry modifying (Win+R, enter "regedit").
Lost in values, using my current screen resolution shows me just a part of the window.
Within the setup exe, I am having no possibility to select a resolution (just 4 graphic cards (D3d, D3d T&L, Intel HD, Intel HD), changing those doesnt have any effect)
Using W 640 H 480 within the registry, then fullscreen within the setup exe doesn't show the window at al
It seems to work for me via 1024 / 768. Also, via setting fullscreenmode within the registry to 0!
1024/768 works, however, graphics (not texts) are highly pixelized!
