If you've downloaded the Adobe Reader installer from the main Adobe website, you've probably noticed that it is not a complete installer. After running it, the installer's first step is to download the rest of the installer. No, you're not the only one that finds this annoying.

Adobe does have full installers available, though they aren't easy to navigate to from Adobe's website. They are available on Adobe's FTP site, which you probably didn't know existed. The current version of Adobe Reader can be downloaded from the following directory:

ftp://ftp.adobe.com/pub/adobe/reader/

From that directory, select the directories that correspond to your operating system, version, and language.