If your Acrobat reader is opening very slow, then follow the given steps to speed up your Acrobat reader,
1. Close all open Windows.
2. Then go to the installation folder of Acrobat Reader.
3. Move ( Cut -Paste) all the files & folders from the "plugins" directory to the "optional" directory.
4. That's all. Now your Acrobat Reader will open as fast as Notepad!!!