In order to downgrade you need to uninstall the current version first. Go to Start -> Settings -> Control Panel -> Add or Remove Programs. From the list of available programs find MultiCharts, select it, click Change/Remove and follow the set up wizard directions. Please note, if you want to keep databases, studies, window positions and other settings, make sure you don’t check Remove MultiCharts User’s Data from Computer. Once MultiCharts is removed you are ready to install the older version of it.