Image via WikipediaQ: My Adobe Reader seems to be getting slower and slower. Can I make it run faster somehow?
A: As Adobe Acrobat Reader gotten older, it lost the word "Acrobat", and it's gotten much bigger and slower as Adobe kept adding stuff into it. If you want a snappy program, you have two choices: slim down the Adobe Reader, or adopt the alternative Foxit Reader.

You can download and run PDF Speedup (scroll down to it), which removes a lot of the plugins in Adobe Reader 9 that nobody uses and slows things down. However, it will also remove the auto-update, among other features.

Or you can download the alternative Foxit reader which is lighter and doesn't have that much "bloat". However, it's not the official reader. It's up to you.