I have a Dell Inspirion 15 7000 series laptop with 4K UHD display and I can not see the scroll bars. Ever. There is a vague sense that there is something there but its not visible nor usable as its too small to get the mouse on it. How do I make it larger? The laptop has a 15.6" display with 3840 x 2160 pixels, (approximately 288 dpi), so graphical elements are about 3x smaller than on a normal 92 dpi screen. Note for example that I've used about:config to set layout.css.devPixelsPerPix to 2.8 from -1 so I can actually see web pages. At -1 the text is extremely small. Tabs, Menus, and drop downs are okay. Just scroll bars and sometimes small drop down carrots are extremely hard to grab. Lastly my fat fingers make it impossible to grab small things using the touch screen too. Please send me info on how to set up Firefox to make small icons bigger. I'm running Firefox under Win 8.1, with everything magnified 250%, and also in Ubuntu 14.04 in a Virtual Box with Guest Additions installed. Thank you.