Google announced that it will no longer permit the silent installation of extensions in its Chrome browser, because the feature has been widely abused by third parties to install extensions without the user's knowledge. As of Chrome 25, external extension deployment options on Windows will be disabled by default and all extensions previously installed using them will be automatically disabled. If previously-silently-installed extensions are found on your system, Chrome 25 will give you a message of which extensions it is disabling, if you want to keep some of them, you can click on the "Extensions Settings" button in the dialog.
For those wondering how silent extension installation works, it’s pretty straightforward. A distributor can use the Windows registry to install extensions en masse; a feature that was originally intended for letting developers to include a Chrome extension as a part of the installation of their software.
Once Chrome 25 is released next year, this will no longer be possible without the user’s knowledge. Google emphasizes Windows application developers should ask users to install Chrome extensions from within the browser; the best way of doing so is to use inline installation.