[wix-users] modify registry value string on install but do not remove registry value on uninstall

[Wesley Manning]

Hi,

My installer is modifying an existing registry value that is not created by my installer. It is of type REG_SZ containing a semicolon delimited list of paths. ("path1;path2").  My MSI on install adds the substring "path3" so that it's now "path1;path2;path3".  To do this I'm using a RegisteryValue element in a component marked Permanent.

Now I have a new requirement to check if the substring "path3" exists on every install and if it does not exist add it again. Permanent will prevent it from being checked again and if I use RegisteryValue without permanent I believe it removes the registry value on uninstall which I don't want.

Is there anyway of doing this other than a custom action?

Wes