Adobe PDF Reader is not on your list of Plug-ins submitted with your question (click on "More system details" to the right of your original question). If it is disabled on the Plug-ins list (''Add-ons > Plugins''), click "Enable". If it is not installed on your system (in your Programs folder), then download the installer and run the installer after it is saved to your hard drive (install with Firefox closed). *See --> [https://support.mozilla.org/en-US/kb/Using%20the%20Adobe%20Reader%20plugin%20with%20Firefox#w_installing-and-updating-adobe-reader Installing/Updating Adobe Reader in Firefox] ('''''NOTE:''''' un-check any items on the Adobe download page that you do not want installed on your system) *Also see --> [https://support.mozilla.org/en-US/kb/Opening%20PDF%20files%20within%20Firefox Opening PDF files within Firefox] '''If this reply solves your problem, please click "Solved It" next to this reply when <u>signed-in</u> to the forum.''' ------------------------- Not related to your question, but... You may need to update some plug-ins. Check your plug-ins and update as necessary: *Plug-in check --> http://www.mozilla.org/en-US/plugincheck/ *'''''Adobe Shockwave for Director Netscape plug-in''''': [https://support.mozilla.org/en-US/kb/Using%20the%20Shockwave%20plugin%20with%20Firefox#w_installing-shockwave Installing ('''''or Updating''''') the Shockwave plugin with Firefox] *Adobe PDF Plug-In For Firefox and Netscape: [https://support.mozilla.org/en-US/kb/Using%20the%20Adobe%20Reader%20plugin%20with%20Firefox#w_installing-and-updating-adobe-reader Installing/Updating Adobe Reader in Firefox] *Shockwave Flash (Adobe Flash or Flash): [https://support.mozilla.org/en-US/kb/Managing%20the%20Flash%20plugin#w_updating-flash Updating Flash in Firefox] *'''''Next Generation Java Plug-in for Mozilla browsers''''': [https://support.mozilla.org/en-US/kb/Using%20the%20Java%20plugin%20with%20Firefox#w_installing-or-updating-java Installing or Updating Java in Firefox]