When it comes to PDF readers we have numerous options to choose from; but, the only one that you will ever need that uses little system resources and gets the job done is SumatraPDF. This FREE reader has been around for years and is one of the first applications I install on my Windows based computers. SumatraPDF is also engineered to read other formats as well; for example SumatraPDF can read: eBook (ePub, Mobi), XPS, DjVu, CHM, Comic Book (CBZ and CBR) formats. What you will really like about SumatraPDF is that it starts up very fast.
SumatraPDF can be installed as normal Windows install or as a portable app. Since I use this on a daily basis here at What’s On My PC, I have SumatraPDF fully installed.