One of the biggest complaints people have about Windows 8 is the lack of a Start button and a Start menu. The video below shows how to use the free software, Classic Shell to replace Windows 8's Start screen with a traditional Start button and Start menu.
Most computer users do not use a PDF document reader often so Adobe's PDF Reader may be a bit on the heavy side because it adds two extra programs to Windows' start up which slows down a computer's boot time. I've tried most of the free alternatives to Adobe Reader such Foxit PDF Reader and Nitro PDF Reader but they were not for me, I settled on Sumatra PDF. Sumatra PDF is small, light, fast and has a nice clean easy to use interface. Sumatra PDF has a great time saving feature up it's sleeve, it remembers the page number and the zoom settings for each document so you can carry on from where you left off, even after you have been reading other PDF documents.