Create a file like this, called options.yml
cat options.yml browser: ie
In your program, execute the following code before calling "Watir::Browser.new":
Watir.options_file = '~/options.yml'
You will need to provide the full path to your file. Once you have done this, "Browser.new" will use the option settings from this file. If you also use an environment variable, it will override this setting.
Currently the following options are configurable for IE:
speed: fast visible: true
Valid speed settings are "fast", "slow" and "zippy"