I've already seen the thread regarding resolution and -w is in the target section of the desktop shortcut (it was like this by default) but it still runs as fullscreen. Any suggestions?

Thanks!

GOG put in a compatibility patch on the windows 8 version so that it always technically runs in a window. it's just borderless. i think the only way to make it work in a normal window is if you make a copy of rebexe.exe and name it something like rebexenew.exe. Then you can make a shortcut to this file and add the -w. - From what I've gathered, the compatability patch requires the games exe file to be called rebexe.exe to make their changes take effect.

I don't know if this will change anything for you or not, I have not tested it. It's just a theory.