Hi,

I have an application for which we use IzPack to create the installer. The installer is working fine in its current state, however, I need to add functionality that enables it to check whether an existing version of the software has been installed.

I understand IzPack supports this out of the box using its CheckedHelloPanel, unfortunately that only works for Windows, as it appears to depend on the windows registry.

Is there a way to configure IzPack such that it is able to detect existing installations?

I need to be able to detect whether there is one and merely display a message notifying the user... Bonus points for how to give the user the option to trigger the uninstaller of the existing installation.

• Assume that the software will only be installed using the new installer
• IzPack only: please do not suggest alternatives, as we cannot change that now
• If you suggest using <validator>, please include a code sample of the validator class, because I have considered this, but don't know where to start