If it's only for reading PDF files, one of the *Moderator's suggested that one can use Sumatra, it is lite and easy to use. I have been using it for over a year and have had no problems with it.
*I don't remember which Mod it is and I already have one foot in the Doghouse
for mistaking a Mod. for another subject.. Soooo I have to be carefull
The official site is here: http://www.sumatrapdfreader.org/free-pdf-reader.html