I recently got asked the question why, if you use the WebBrowser control in a WinForms app to display a PowerPoint presentation, a vertical scrollbar is displayed even if you set ScrollBarsEnabled = False.
Well, I did a bit of digging... Try doing the same thing in IE (I wish I'd tried that about 30mins earlier rather than playing with various properties!) and you get the same effect - so clearly not specific to the WebBrowser control then. My attentions switched to whether I could modify the PowerPoint presentation to prevent this happening.
I tried a variety of combinations and eventually settled on modifying the "Show Type" and saving as a PowerPoint Show (*.pps). Access the "Show Type" from "Slide Show" -> "Set Up Show" and modify the "Show Type" to "Browsed by an individual (window)" and uncheck "Show scrollbar" (see right):
The net result - no vertical scrollbar. You can still navigate the PowerPoint deck using either the keyboard or the context menu.
There are probably other (better) ways to do it. If you know one, do let me know!