Make sure you make rotation on the playfield monitor 270 degrees (Sideways) and arcade mode and full screen are checked (you should check these for the backglass as well). Set the resolutions accordingly for display 1 and display 2 (presumably playfield and backglass respectively). Enable arcade mode for your playfield monitor and your backglass monitor from the drop down menu under video settings. Go into FP and open the Video/Rendering options under preferences.
Right click that shortcut and add '/arcaderender' without the quotes after the text in the quotes on the line that says Target (make sure you leave a space between the quotes around the shortcut text and the text you add). Create a shortcut on your desktop if one isn't created.
