Browser plug-ins are a mixed blessing. They add useful functionality, but at the same time heighten your risk of viruses and other malicious code by increasing the browser attack surface. This is always a trade-off and sometimes the inconvenience of making sure the latest security updates are installed is worth the hassle. Google Analytics and Xero without Flash, for example, would loose their interactive graphs greatly reducing the functionality of both applications.
However, there’s a difference between a plug-in you’ve chosen to install, and one that just installs itself along with another piece of software. Worse still are those plug-ins that you just can’t uninstall. iTunes is particularly annoying in this regard, there’s no uninstall and deleting the plug-in files causes iTunes to reinstall itself (and the plug-in) on next run. Sure you can disable the plug-in in the browser, but I’d prefer it not to be there in the first place.
After looking into this further, there is a way to permanently block unwanted plug-ins without deleting the files (which just causes iTunes, the .NET Framework Firefox plug-in, and many others to reinstall themselves). The trick is to create another Administrator user account on your machine, and use that account set file permissions on the plug-in to block access from your normal user account. Without ‘read’ rights to the plug-in file, there’s no way it can load into your browser disabled or not.
Locating the plug-in files to block is pretty straight forward if you know where to look. In Internet Explorer it’s under: Tools > Internet Options > Programs > Manage Add-ons. Once in the ‘Manage Add-ons’ dialog you’ll see a ‘File’ column with the plug-in’s filename, right clicking on the column heading and checking ‘In Folder’ will also show you the paths to these files. In Firefox the plug-in list is displayed by typing “about:plugins” in the address bar. Unfortunately you’ll need to figure out the file paths yourself, as Firefox doesn’t tell you this.
Once blocked, your browser plugins list will be reduced to just those that you need and want, in doing so making your browser more stable and secure.