Normally you should use SetWinSize or SetWinRect instead of this command to change a window's size.
This command is designed to be used only when both of the following circumstances exist:
1. The target is a program like Aion that requires resizing to be done with a mouse, and
2. The target's window is frameless.
If 1 is true but the window has a frame, use SetWinSize or SetWinRect with "SimMouse."
This command doesn't work perfectly yet (the frame isn't always removed at the end.) Specifying a delay of around 55 seems to help on my test PC.
This command changes the size of the window that was targeted with TargetWin, TargetChild, SendWin, etc.