There are many freebies and downloadable applications for the Windows operating system. The one I like best is the AccuSpell application. This software was designed by a company called SpellEasy, Inc., that is owned by Andrew Hemming, a former Microsoft employee. The AccuSpell software is free for personal use, but you can purchase it as a stand alone program or you can download it and save it to your computer for a one time fee.
The download link for the free version is located on the website SpellEasy.com. You can click the link and begin downloading right away. If you have some experience in using Microsoft Word, then you should be able to navigate the interface quite easily. Once you have downloaded the application, you will be prompted to install it, and this is done by clicking on the "install" button. Once the application is installed, the next step is to choose a new spell checker.
Once you choose a new spell checker for the free version, you will then be asked to provide some information about yourself. This information is used to help AccuSpell determine how accurate the spell checker is. After you enter your information, a list of the most frequently used words and terms will be listed. This should give you a good idea of what your perfect spelling is.