I know this answer is 5 years too late...
To update your favicon image you have two options:
- Place the desired
ico
image in yourskin/frontend/<package>/<theme>
directory (as suggested by St3phan above) - Upload your
ico
image to themedia/favicon
directory and create acore_config_data
row with a value pointing towards it.
You can look at app/code/core/Mage/Page/Block/Html/Head.php
_getFaviconFile()
to see how the favicon file is loaded.
While there is the System->Configuration->General->Design->HTML Head->Favicon Icon
field you can supposedly use to update your favicon image, it does not work for ico
files. This is due to the validation that is run during the save process in app/code/core/Mage/Core/Model/File/Validator/Image.php
which calls imagecreatefromstring
(see https://www.php.net/manual/en/function.imagecreatefromstring.php) which will always return false because it does not support ico
files.