While upgrading Confluence in Windows via Installer, sometimes the running version of Confluence can't be stopped. This ends up in pop-up Errors in installer.

It will be good to have the following messages in pop-up, when this situation happens

1. Confluence might be running, please shut it down before upgrading
2. Confluence's home or installer folder might be open by a program like (File Explorer or cmd). Please close them and try upgrade again

This will make admins more aware of the scenario.