If you are a registered user of WGCalculator you may upgrade at no charge to newer minor release. Just download the latest shareware release of WGCalculator (Version must have an alike major version number as your) and install it without uninstalling the previous version (don't forget close previous version of WGCalculator if running). This will preserve your registration. If the registration code is no longer present on your system just re-enter it like the first time and restart the program.