Configuring the Flash Player

Gregg Wygonik blogged about this yesterday. He was looking for a way to automagically disable the auto-update feature of the Flash Player for a long time. I remember the response from Macromedia at the time was that there was a way to do this for enterprises, but it was not documented. This gem is now available in Flex documentation.

Of course you can also disable the update using the Global Notification Setting Panel manually, but by using the mms.cfg approach you can set a new URL for the update.

So in a corporate environment, not only you can deploy auto-update disabled Flash Player installation, you can leave the auto-update feature on, configure the auto-update settings: The URL for the version XML and Installer, etc. And actually control the auto-update…

The settings in the mms.cfg file takes precedence over settings otherwise stored in a local shared object. Is this secure? I’m not sure. An ill intended application can modify the mms.cfg file easily, its name and location is fixed. Is it possible to set and install a fake update this way? I hope not.

One interesting setting there, which I’m not aware if available in any other way, is WindowlessDisable. If you set the value to 1 you may ‘suppress windowless content from playing’. I like this one…

This entry was posted in Flash.

10 Responses to Configuring the Flash Player

  1. JesterXL says:

    Is that another way to say, “Disable annoying Flash banner ads?”
    If it’s WMODE is equal to transparent?

  2. Exactly. And it works :)

  3. g.wygonik says:

    thanks for posting about this. i thought i was alone in my joy. :-)
    be aware, however, that the “windowless” killing option also effects the “opaque” setting – not just “transparent”.
    “opaque” is sometimes set to allow the browser to catch mouse events over the Flash movie – like trapping and killing the right-click context menu.
    if you see a black area where a non-ad Flash movie should be, it is probably set to “opaque”. (“transparent” will still show the background color of the HTML page) :-)

  4. Fernando says:

    Lots of sites uses wmode transparent, so disabling it can cause you problems.

  5. How to Disable Floating Flash Ads

    Via ASVGuy & Gregg Wygonik Gregg found some documentation in the Flex LiveDocs on how to disable the Flash Player’s auto update feature. This is helpful for IT Admins. Burak KALAYCI(ASVGuy) dug a little deeper, and explained a little bit…

  6. Vera says:

    Is this some kind of joke? ;-)

  7. ? I’m still thinking about a prank post, this one is not.
    Well, I’m OK with ads either Gif or Flash, as long as they stay in the box they should stay. I find windowsless Flash ads that obscure the text I’m reading really annoying.

  8. Mumbai Flash says:

    Log Flash trace() to a text file

    Read how to log the Flash trace() output to a Text File, also read how to disable auto update and windowless flash movies from playing in your browser. Via : g.wygonik…

  9. It sucks when your links go dead…
    The Flex doc link is now at, thanks to google: flex/15/flex_docs_en/00000941.htm
    In case it goes dead again, I’m pasting the text here:
    Managing Flash Player auto-update
    Flash Player supports auto-updating itself by periodically checking for new versions of the player on the site. IT administrators can customize the parameters of this update.
    The auto-update settings can be configured in two ways:
    User settings in Flash Player
    mms.cfg file in user’s “home” directory
    Users can disable the auto-update process or set the periodicity of the checks by using the properties panel in Flash Player. These user-configured auto-update settings are stored in a local shared object.
    The second method for configuring the auto-update settings is to create a file named mms.cfg. The mms.cfg file is intended to be configured by an IT administrator and stored on the user’s computer. The file is not created by Flash Player installation. You might use a third-party administration tools, such as Microsoft System Management Server, to replicate the configuration file to the user’s desktop.
    Store the mms.cfg file in the following location, depending on your operating system:
    Windows NT, 2K C:/WINNT/System32
    Windows XP C:/WINDOWS/System32
    Windows 95, 98, or ME C:/Windows/System
    Macintosh /Application Support/Macromedia
    The format of the mms.cfg file is a series of name=value pairs separated by carriage returns. If a parameter is not set in the file, Flash Player assumes the default value. When set, values in this file override the user-configured settings.
    The following table describes settings in the mms.cfg file:
    Parameter Default Description
    00 allows auto-update based on user settings.
    1 disables auto-update.
    String specifies URL as download location for player update.
    If this parameter is not set, Flash Player uses the Macromedia server.
    <0 (or absent)
    <0 (or absent) uses value from player settings.
    0 checks for updates every time the player launches.
    >0 specifies the minimum number of days between check for updates.
    String specifies URL as destination for “Settings…” button in auto-update dialog.
    If this parameter is not set, Flash Player uses the Macromedia server.
    Specifies the URL to retrieve XML file containing Flash Player update data.
    If this parameter is not set, the player uses the Macromedia server.
    To disable the auto-update:
    Open the mms.cfg file in a text editor.
    Add the following auto-update setting:
    Save the mms.cfg file.
    Close and restart Flash Player or the browser in which Flash Player is running.
    You are not required to remove any other settings so that you can re-enable the auto-update feature and restore your original settings by removing this line (or setting its value to 0).

  10. More recent doumentation is available at: