You can speed up the amount of time it takes Adobe Reader to boot by renaming one file in “Program Files.” Arsgeek explains how to do this very nicely:
I installed Acrobat Reader 8.0, and every single time I open a document, I was presented with a “please wait while the document is being prepared” message, that would sometimes stay for minutes as it indexed the entire document. This presented issues with both usability, and when giving presentations.
To remove this ‘feature’, simply navigate to your %Program Files%\Adobe\Reader 8.0\reader\plug_ins folder, and rename (delete, copy elsewhere) the ‘accessability.api’ file. The same file exists, but in slightly different locations, in older version of Acrobat Reader.
Poof! No more annoying messages preventing you from actually reading the file. Keep in mind, the ‘reader’ functionality will no longer work.
If you try this let us know how it goes in the comments. If you hate Adobe Reader, you can always ditch it for Foxit Reader.
Adobe Acrobat Reader got you down? – [Arsgeek]