Mozilla Firefox:

  1. Open Mozilla Firefox
  2. Go to about:preferences#applications or Click on Open Menu / Options / Applications
  3. Change the Default Action for Portable Document Format to Adobe Reader
  4. Restart Mozilla Firefox

Internet Explorer:

  1. Open Internet Explorer
  2. Click on Settings / Manage Add-Ons
  3. Click on Show All Add-ons
  4. Change the Status of Adobe Reader to 'Enable'

Google Chrome:

  1. Open Google Chrome
  2. Enter URL chrome://settings/content in the search bar and hit ENTER
  3. Scroll down to PDF Documents > Enable “Open PDF files in the default PDF viewer application”
  4. Click DONE to save changes