Hey Steve,
-Cancel the installation
-if you have any kind of Anti-Virus/Security software (ex: Norton, MacAfee, etc.), turn it off temporarily. Programs like these can sometimes block full installs or uninstalls.
-uninstall the current version of CB2020 Pro you have on your computer through your Windows Settings>App List
-install the revised CB2020 Pro installer and see if you get further through the process.
If you still have trouble, please contact us at support@comicbase.com OR 408-266-6883