Customize MSI Installation - User Interface Dialog

Question

Hi All, I am customizing installation by providing Checkbox dialog in User Interface Editor. Say, I am providing 4 checkboxes and all of them are checked by default. First time when user installs the application, all the checkboxes will appear as checked. User unchecks 2 of them and proceed with the installation. Now the installation is completed successfully and 2 components out of 4 are installed on his machine. Now, when the user runs the MSI again, I want to show 2 checkboxes checked and 2 unchecked (since two omponents are already installed on his machine). How can I achive this??? Any pointers on this would be of great help. Thanks,