You can get totally free and fully operational spelling checkers from many sites (I suggest that you get one from a publisher that has an international reputation, as well as being reliable, trusted, etc. This would include Merriam-Webster's Abridged (their site is http://www.merriam-webster.com), or the most highly respected and best, The Oxford English Dictionary & Thesaurus. You can access the complete 20 volumes via local libraries - you'll enter your library card number and have complete online access.