For Internet Explorer 9: Click the settings icon (it looks like a gear and is in the upper-right corner) or use shortcut Alt+X and then click “Manage Add-ons”. On the left side, select “Toolbars and Extensions”, and then right-click on “Shockwave Flash Object”. Choose “More information”, and in the popup window click on “Remove all sites”, and then close the window. Take the same action for Microsoft Silverlight, Adobe Reader (it will be called Adobe PDF Link Helper), and the Java Plugin (it will be under Sun Microsystems or Oracle Corp).
For Firefox: In the address bar, type about:config and press enter. Search for “plugins.click_to_play”. Double-click it to change it’s value from false to true. In newer versions of Firefox it already be set to true.
For Google Chrome: Open the configuration settings menu (type chrome://settings in the address bar and hit enter), at the bottom select “Advanced settings”. Under the “Privacy” option, click the “Content settings” tab, then under Plug-ins enable “Click to play” and click OK to save the setting.
For Opera: Click the Opera Icon in the upper-left corner (or press Alt) then click Settings and choose Preferences (or press Ctrl+F12). Click on the “Advanced” tab and click “Content” on the left. Click the check-box that says “Enable plug-ins only on demand” then click OK.