Install another MSI if no registry key is found

[Nagash_42]

I'm evaluating InstallShield and am getting quite confused on how to accomplish simple conditions in the installation process. My problem is as follows: I need to Install MS Word Viewer because the application I am installing needs it as a precondition. If it already is installed, I just want to write the command as found in the registry under "HKEY_CLASSES_ROOT\Applications\wordview.exe\shell\Open\command" to a text file. I thought I could check if said key is in the registry and otherwise call Word Viewer's .msi. I can check for the key by using the System Search or in a custom InstallScript using the RegDBKeyExist function. But that's as far as I get. How do I start the .msi depending on if I found the key? Can I just use the INI-file change tool to write the key to my file?

[Nil_Developer]

I think you r using installscript msi project.You can install msi using below installscript code.

if(RegDBKeyExist(" ") ==1 ) then

//do nothing
else
LaunchAppAndWait (SUPPORTDIR^"msi name", "/qn", LAAW_OPTION_MINIMIZED | LAAW_OPTION_WAIT);
endif;


Regards
Nilesh

[Nagash_42]

Thank you for your help.

If I call the installer like this, would I have to remember this installation (in the registry? a .ini?) and undo it in the uninstall (how?) or can I somehow make InstallShield uninstall the included .msi if it was installed by the installation?

Can I use a prerequisite to do this? Will a prerequisite be uninstalled if it was installed only for my app?

[Nil_Developer]

You can uninstall MSI when you uninstall your application.

For uninstall you can find string in registry :HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\ Product_Guid.

search for uninstall string in above key.

I never used prerequisite. But as per logic it should uninstall when you will uninstall your application.