...and set the Software installation of Google Chrome to reinstall/deploy. But it didn't work. No Adblock Plus extension.
Here is the full text of the "Configure the list of force-installed extensions" property:
Allows you to specify a list of extensions that will be installed silently, without user interaction.
Each item of the list is a string that contains an extension ID and an update URL delimited by a semicolon (;). The extension ID is the 32-letter string found e.g. on chrome://extensions when in developer mode. The update URL should point to an Update Manifest XML document as described at http://code.google.com/chrome/extension ... pdate.html. Note that the update URL set in this policy is only used for the initial installation; subsequent updates of the extension will use the update URL indicated in the extension's manifest.
For each item, Google Chrome will retrieve the extension specified by the extension ID from the update service at the specified update URL and silently install it.
Users will be unable to uninstall extensions that are specified by this policy. If you remove an extension from this list, then it will be automatically uninstalled by Google Chrome. Extensions specified in this list are also automatically whitelisted for installation; the ExtensionsInstallBlacklist does not affect them.
If this policy is left not set the user can uninstall any extension in Google Chrome.