Many plug-ins are integrated into the browser and you do not need to install them. Others are installed automatically, or there may be links from a page that requires their use to a download site. If they are not pre-installed or linked from a page, you can go to various sites to find them. You may also need to upgrade to a new version. Some common plug-ins are:

Acrobat Reader

Available from Adobe at http://www.adobe.com/products/acrobat/readstep.html

Shockwave Player, Flash Player, and Authorware Player

Available from Macromedia at http://www.macromedia.com/software/downloads/

QuickTime

Available from Apple at http://www.apple.com/quicktime/download/

Realplayer

Available from RealNetworks at http://www.real.com
(Basic edition is free; additional versions available for a fee)

Windows Media Player

Available from Microsoft at http://www.microsoft.com/windows/windowsmedia/en/default.asp

Microsoft, Netscape, and America Online also provide links to commonly used plug-ins from their company websites.