The short answer is yes. You can use one of two methods to achieve the result.
Install the Images for Titles mod from Free Addons, following the instructions in its readme.
Upload an image file for each sidebox heading you want to substitute, named (for instance) boxhead-categories.gif in the case of the Categories sidebox. Save the image in /includes/templates/CUSTOM/buttons/ENGLISH/
.
If you want to use other than .gif files for the images, edit the define in /includes/languages/ENGLISH/extra_definitions/CUSTOM/image_titles_defines.php
.
This method automatically removes the [more] that follows a replaced heading link; but it does require that the same image type (gif, jpeg, png) be used for all replaced heading images in an area.
...CAPITALIZED words refer to a folder or language that you choose. We use CUSTOM for your template and ENGLISH for your language by default. These generic terms should be changed to the name of the template/language you are using.
If you want to change "Congratulations! You have successfully installed your Zen Cart®; E-Commerce Solution" with your own text open the includes/languages/ENGLISH/index.php file and find the following code:
// This section deals with the ...
CAPITALIZED words refer to a folder or language that you choose. We use CUSTOM for your template and ENGLISH for your language by default. These generic terms should be changed to the name of the template/language you are using.
/images folder: This is where your Product images are located.
/includes/languages/ENGLISH/images folder: icon.gif (your language flag).
/includes/templates/CUSTOM/buttons/ENGLISH folder: contains the buttons used by ...
CAPITALIZED words refer to a folder or language that you choose. We use CUSTOM for your template and ENGLISH for your language by default. These generic terms should be changed to the name of the template/language you are using.
Look in includes/languages/english.php. Suppose you want the Categories sidebox to have a different title. Look for
define('BOX_HEADING_CATEGORIES', 'Categories');
Changes for additional sideboxes will follow this pattern:
define('BOX_HEADING_XXXXXXXX', 'New Title