Adobe Flash Player, also known by its former name Shockwave Flash Player, is a multimedia plug-in that powers YouTube, simple online games and zillions of ads on most Web browsers. However, it's also a huge security risk, especially when it's set to automatically start playing compatible content.
To maximize your Web security and defeat the seemingly endless supply of malware that exploits the innumerable flaws in Flash Player, you should change your browser settings so that Flash Player plays only the content that you select by clicking on it.
This way, you'll still be able to watch YouTube videos in older browsers (newer ones use HTML5), but you won't be bothered by annoying animated ads or infected by malicious websites and ads.
How to set Flash to click-to-run in Mozilla Firefox
1. Click the three stacked lines in the upper right of the Firefox browser window.
2. Click Add-ons in the resulting drop-down menu.
3. Set Adobe Flash, Adobe Flash Player and/or Shockwave Flash to Ask to Activate.
How to set Flash to click-to-run in Google Chrome
1. Click the three stacked lines in the upper right of the Chrome browser window.
2. Click Settings.
3. Scroll down and click Show advanced settings.
4. Scroll down to the Privacy section and click Content settings.
5. In the resulting pop-up, scroll down to Plug-ins and select Click to play.
How to set Flash to click-to-run in Microsoft Internet Explorer
1. Click the gear icon in the top right corner of the Internet Explorer browser window (the one just below the red X, not the one on the Internet Explorer homepage).
2. Select Manage add-ons.
3. Select Toolbars and Extensions in the left navigation window of the resulting pop-up.
4. Find Shockwave Flash Object in the right results window. If you don't see it right away, make sure the drop-down box labeled Show is set to " All add-ons."
5. Right-click Shockwave Flash Object and click More Information.
6. Click Remove all sites in the resulting pop-up window. It's underneath the large form field labeled "You have approved this add-on to run on the following websites." The field may display an asterisk; you want that asterisk gone.
How to set Flash to click-to-run in Apple Safari
1. Click the Safari menu in the top left of the computer screen.
2. Select Preferences.
3. Click the Security tab in the pop-up window.
4. Click Manage Website Settings.
5. Select Adobe Flash Player in the left-hand navigation window.
6. Clear the field labeled "Allow websites to use this plug-in with the settings below" in the right-hand results window by closing out the browser window behind the pop-up (by pressing the red button in the upper left-hand corner).
7. Set the drop-down selection next to "When visiting other websites" to "Ask."
Jill Scharr is a staff writer for Tom's Guide, where she regularly covers security, 3D printing and video games. You can follow Jill on Twitter @JillScharr and on Google+. Follow us @tomsguide, on Facebook and on Google+.