Firefox
On the top menu bar of your browser click on the last icon on the right (three stacked lines) and choose “Options.”
On the Options screen scroll down to “Applications.” Scroll down the list to find Portable document Format (PDF) and set it to whatever you like: Firefox Viewer: Adobe Reader: etc The default is usually Download. If you set it to Download then the file will not open automatically. You will need to check your Download folder and open it from there.
Google Chrome
Click on the three stacked dots on the extreme right of the address bar and select “Settings”
Scroll to the bottom of the Settings screen and click on “Advanced”
In Privacy and Security click on “Content settings”
Scroll down to PDF Documents and click on the gray arrow on the right.
The next page shows a selector button to the right of a sentence that begins “Download PDF files instead….” If the slide button on the right is white, then Chrome will display the PDF file. If it is blue then the PDF file will automatically download to your machine. The default is usually white to display the PDF files.
Internet Explorer and Edge in Windows 8 and above
From your desktop click on the lower left-hand corner Windows icon and choose “Settings” (the Gear icon)
On the Settings menu choose Apps, then Default Apps
Scroll down Default Apps and find “Choose default apps by file type.”
Now scroll down the page until you find .pdf in the left hand column. To the right of PDF Windows will display either “Choose a Default” or display the current setting. To change the setting just click on it and choose how you want .pdf files handled.