Re: Changing windows xp to portrait mode.
First, we don't support pirated software on these forums so I'm not going to try and troubleshoot the MAME software. If it's your entire display that is 'sideways', then that is most likely a screen rotation function of your Graphics Controller/Driver. Some graphics controllers (I think older NVIDIA?) will allow you to rotate the screen by simply holding CTRL and pressing a directional arrow. Other controllers such as Intel's onboard HD controller, require you to right-click on the desktop and select the Graphics options menu item and then go from there. A larger number though actually require you to get into the Controller software suite and then find the screen/display rotation settings. If it's limited to this one program though, there's not a lot options for changing view options outside of the program itself.
Humans are the only creatures that won't live up to the their potential. Give everything your all. When you die, die on E.
So I ask you, what do you intend to do now?