In my windows machine, I havent installed any PDF reader since I was not using windows system often. Yesterday I came across a light weight PDF viewer for windows by name Sumatra PDF viewer. http://blog.kowalczyk.info/software/sumatrapdf/
I liked it very much for the following reasons:
1. Its light weight compared to Adobe Acrobat reader.
2. It serves its purpose of showing the pdf files cleanly.
3. Its a freesoftware .
I have installed it and started using it as my primary and only PDF viewer.
Of cource it has few sortcomings too. Right now it doesnt have printing support. But I hope soon these features will be available since its a freesoftware. And by nature freesoftwares evolves thro community participation