In order to add a spellchecker your WYSIWYG editor, it makes sense that you first need a WYSIGYG editor installed. In this example we're using TinyMCE. Click here for our instrucitons on installing TinyMCE.

We're going to install the Wysiwyg SpellCheck module: http://drupal.org/project/wysiwyg_spellcheck.

This installation will take a few minutes at least, so please follow these steps carefully.

In writing this tutorial, only the Development release worked successfully for me. It might be worth trying the Recommend release first and then th Development release if that doesn't work for you.