I sometimes have the same problem when I remove my laptop from the docking station. Usually if I change my screen resolution to something different and then change it back, the windows open up properly.
If that doesn't work, this might (I'm not sure if these legacy accelerator keys are still valid in Windows 8): Right after you invoke the "new" dialog box, it should be the active window, even if it is off screen. While it is active, press the alt key, then the down arrow, then the M key. This will let you manually move the window with the arrow buttons. The button combination may be different for different windows (you might have to push the left arrow key, then down depending on the program) but that should work for the "new" dialog box.
Hope that one of these solves your problem.