Opera

Adobe Acrobat Reader is a free reader of .pdf files from Adobe Systems Incorporated.

1. Download the program from http://www.adobe.com/products/acrobat/readstep2.html. If you have difficulty downloading, go here.
2. Close Opera
3. Double-click the downloaded file to start the installation wizard. Follow the on-screen instructions to install the program.
4. Find the file "nppdf32.dll" in the plug-in's folder (it can usually be found in C:\Program Files\Adobe Acrobat\Reader\Browser). Copy this file to Opera's Plug-ins directory (by default C:\Program Files\Opera\Program\Plugins).
5. Open Opera. Opera will locate the "nppdf32.dll"-file and associate it with the Adobe Acrobat Reader. Now Opera will launch the Acrobat Reader when you use Opera to view .pdf-files.

You can change the way Opera opens the PDF documents in Tools > Preferences > Advanced > Downloads Edit the MIME type assosiated with pdf files to either "Use plug-in" or "Open with default application".