Taming Google Chrome for Windows and Moodle


Seeing as IE9 doesn’t support the very handy drag and drop features in Moodle 2.4 and IE10 has a habit of breaking other internal web services we’re installing Google Chrome on our Windows 7 image this year. On the face of it the installation and configuration is pretty simple but there are a couple of tips and gotchas to watch out for…

Auto open attachments

Love them or hate them Office files still exist in Moodle courses in terms of providing resources to students so we wanted to check what Chrome’s behaviour would be when they’re clicked. In IE you get the classic “Save or Open?” dialog box but Chrome just plonks the files in the Downloads folder, no questions asked.

That’s not so good as it means users have to hunt around for files and manually open them, not liking that at all so set out to find a better way. Nothing in the standard preferences GUI but a bit of research found that it is possible to set certain attachments to auto-open by using a file called master_preferences which you can find in C:\Program Files\Google\Chrome\Application

Ref: https://support.google.com/chrome/a/answer/187948?hl=en
Ref: http://www.chromium.org/administrators/configuring-other-preferences

The master_preferences file is in JSON format and any slight typos will stop it working so use something like http://jsonlint.com/ to verify your finalised settings when done.

The setting you want is called extensions_to_open and looks something like this:

"extensions_to_open": "doc:docx:xls:xlsx:ppt:pptx"

Note: some of the settings you can enable in master_preferences are better to configure via the Group Policy ADM files as preferences are exactly what they say on the tin and as such won’t prevent the user from changing them.

A sample version of the master_preferences file we used can be found in SkyDrive

Disable access to C: drive

Most admins know about the standard Windows GPO to disable browsing \ access to the C: drive but what you may not know is that Chrome basically ignores it and still allows users to access the local HDD by typing file://C:\  into the browser window!

Fortunately my colleague Barry Whitehouse found a setting in the Chrome ADM to disable this but it’s not immediately obvious:

Computer Settings > Administrative Templates > Google > Google Chrome > Disable URL Protocol Schemes then enter file in the settings box

Desktop shortcut

As we’re using ZENworks to push out all our desktop shortcuts we didn’t want Chrome creating its own one, in theory this should be controlled via master_preferences but there’s an outstanding bug in the code that means Chrome ignores the setting. Hopefully will be fixed in the future, the just a matter of keeping an eye on the dev forums for when it finally gets sorted.


3 Responses to Taming Google Chrome for Windows and Moodle

  1. Steven says:

    Seems “Disable URL Protocol Schemes” doesn’t exist anymore in the ADM / ADMX files ?

    • gshaw0 says:

      Oddly enough I’ve been importing a whole bunch of ADMX files into our new AD Central Store today; just checked and I can’t see it in the latest policies either.

      Did a bit more digging and although DisabledSchemes still exists in chrome://policy it’s apparently a deprecated feature according to the development documentation:


      Looks like URLBlacklist is the way forward, which corresponds to a setting that does exist in the ADMX and is called:

      Block Access to a list of URLs

      Give that a try and if it works I’ll update the post.

      • Steven says:

        Hi GShaw

        Thanks for your reply!

        I’m offering internet via Chrome on Citrix to our users. My main concern was blocking the servers file system and executing downloaded files.
        Blocking URLs with “file://” didn’t work, but now I tried again with “C:\”, and that seems to work well.
        Setting the download directory to “NUL:\” solved my download-problem.

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