Adobe's PDF Reader and Acrobat software are up there pretty high on my list of bloated windows software that I'll never put on a Windows maching I get. Its slow, bloated, and takes forever to launch, which is particularly annoying when you want to read something right now! Viw Download Squad, comes news of Sumatra PDF viewer which is free, fast, tiny, and Open Source.
Sumatra is a single 802KB executable file for Windows. No installation required. That means you can run Sumatra off of a flash drive. You can also set it as your default PDF viewer.
I linked to a negative review of Adobe Acrobat 6 four years ago!