Some Internet video content and animations won't display in your browser properly if you don't have the latest version of Adobe's Flash Shockwave Player installed and configured correctly. While being spared Flash-based banner ads may be no bad thing, you'll probably find being unable to view your favourite streaming video clips and catch-up TV services somewhat less of a blessing. If your installation of Flash appears to be playing up, you can check it out and get troubleshooting by using Adobe's Online Flash test tool.
Navigate to Adobe's "Test Adobe Shockwave Player" page. If you see an animation playing in a labelled box, you have a working version of Flash installed for your browser. Depending on which browser you're using, you may be prompted to download an add-on to get Flash working properly.
Click on the "Test your Adobe Flash Player installation" link to check you're running the most up-to-date version of the software. You'll be presented with a list of the most recent versions of Flash for a range of operating systems and browsers. Click though to the "Player Download Center" to update to the latest version if you're running old software.
Flash is integrated and enabled in Google's Chrome browser by default and updates automatically. If you're having trouble streaming video content despite having a working version of Flash installed, you may need to download another player such as Microsoft's Silverlight.