PDF Documents in Firefox
You may have issues viewing .pdf files in Firefox. This is most commonly caused by two issues.
Issue #1- You don't have Adobe Reader installed
Solution- Install Adobe reader from http://get.adobe.com/reader/. Be sure not to install any optional software they offer. Most of the time you have to uncheck a box to reject optional software. Note: You will need administrator access to install Adobe Reader.
Issue #2-Default applications in Firefox are set wrong.
Solution- When in Firefox press the ALT key on your keyboard. At the top of the screen where the "File" menu popped up, select Tools and scroll to Options. Under the applications tab of the options menu, scroll down until you see "Portable Document Format (PDF)". This option needs to be set to either "Use Adobe Reader (default)" which opens the document in a different window, or "Use Adobe Acrobat (in Firefox)" which opens the document in the browser. A picture of the options window is below.