Hello Dennis,
Although Adobe Acrobat Reader is the commonly used PDF reader. It is not longer the best one IMO, neither it is the most efficient one when it comes to resource utilization. I dumped it many years ago and I haven't bothered with it since then.
Anyway, after trying few I settled for Fox It, it is smallish, pretty damn fast and does all what I need to do, so I would suggestion you to have a look at it as well. Regards
link:
http://cdn01.foxitsoftware.com/pub/foxit/reader/desktop/win/5.x/5.0/enu/FoxitReader501.0523_enu_Setup.exe