How to use Mozilla Gecko in TopStyle

To use Mozilla Gecko in TopStyle, you need to download, install, and register the Mozilla Gecko layout engine:

  1. Download the Mozilla Gecko layout engine (release
  2. The download is a zip file, not a true install. Unzip this file someplace reasonable onto your machine, for example: "C:Program Files\XULRunner" (no quotes).
  3. Windows 2000 or Windows XP:
    Click Start > Run from the Windows menu, enter "cmd" (no quotes), and click the OK button.
    Windows Vista or Windows 7:
    Click Start, and locate the "Command Prompt" menu item (buried deep inside Accessories under All Programs). Right click on "Command Prompt". On the pop-up right click context menu, select "Run as Administrator".
  4. Change to your XULRunner directory (e.g. "cd C:\Program Files\XULRunner").
  5. Type "regsvr32.exe mozctlx.dll" (no quotes).

Note that you must use the above installer before using Mozilla Gecko inside TopStyle, even if you already have FireFox installed.

If after installing Mozilla Gecko you receive an error message in TopStyle stating that Mozilla Gecko couldn't be created, you may need to register it again to get it working (see steps above).

Important: While we're happy to offer Mozilla Gecko in TopStyle, please understand that the reliability of this feature is out of our control. Because of this, we cannot provide technical support for this feature.