I stumbled upon an old thread here in the IAHGames forums, concerning a problem that I had as well. The game client configuration window is not optimized for 1024x768 resolution, resulting in an elongated window which extends beyond the screen.
Viper17 has kindly provided a solution using an alternative geconfig.exe file. Simply download the file and replace the one in Granado Espada\release folder. Backup original file first, if desired.