I am creating a single .msi installer. If the .msi file is run when the program is already installed, a message box is displayed, prompting the user to uninstall a previous version. What I would like to do is automatically overwrite the existing version with an updated version of the software.
Is this as simple as selecting a checkbox somewhere in the installer to enable this?
It sounds like you want your new installer to Upgrade the old version. You probably want to author an entry in the Upgrade table using the Upgrade Code from the old version. In that same entry, you can set it up so that the installer will automatically uninstall that old version.
This is called a "Major Upgrade".
Look in the help for Major Upgrade and you should find enough details there to get your Upgrade table setup to detect the old version.
