hello jmcohen..

It should be noted that currently there is no built-in feature that can save webpage as PDF in Firefox. Thus you may not be able to save pages as PDF if you are using an earlier Windows version other than Windows 10.

Run Firefox browser on your Windows 10 PC. Visit the website in Firefox. Click to open the File menu at the top left corner of the Firefox browser window. (Can’t see the menu bar in Firefox? right-click in a blank area at the top of your browser window, a drop-down menu will be displayed. Left-click to select and show menu bar)You will see a drop-down menu.

• Choose Print Preview, then the print preview page opens.
• Click Print in the dialog window, then the Printer settings in Windows 10 will pop up.

tell me its help

GREETING FROM: arman

It is possible that you have set Firefox as the default application to handle PDF files in Windows when downloading a PDF file.
Firefox 78+ releases offers a choice to open PDF files that would normally be saved or opened in an external application in Firefox.
See "What's New" in the "3-bar" Firefox menu button drop-down list.

You can disable this new feature by setting this pref to false on the about:config page.

• browser.helperApps.showOpenOptionForPdfJS = false
• https://support.mozilla.org/en-US/kb/about-config-editor-firefox

Hello Arman and cor-el, Thank you for your responses, but they didn't help because they didn't address what I wrote. 1. This change (which I did NOT do) affected several thousand pdf files on my computer and 2 external hard drives. There was an automatic change from pdf to Firefox html files with pdf file extensions. 2. This computer is not running on Windows 10. 3. Something happened the last time that Firefox updated. It changed the "default documents" for pdf files on my computer. I was able to override what Firefox changed. Now, all of the thousands of pdf files ARE pdf file.

Try to open a PDF file in Windows Explorer and select your preferred PDF viewer (you may have to press the Shift key if you click Open in the right-click context menu if Open with isn't available). If you tick the box to use that application always then this should be sufficient to recover from this change.

cor-el, please read my response above. I had to go to Start-> Default Programs. I was able to "fix" the problem there. My question remains: WHY did this occur? It seems to have been a result of Firefox's last update. Thank you.