Anyone have a thought on this?

I want an app, say installscript or windows installed or MS .net
framework 1.1 application that I can chain to other applications. So
far so good, I have this already.

However I'd like the application to see if it's already installed
because sometimes attempting to install it again causes an error.

If I just put in conditions in the availability to check if it's
installed, then it becomes unavailable, if it's already present (say
installed via windows update instead of zen), as it should. But this
then kills the availability of any application chained to it.

Is it possible in the run scripts for me to check the registry and say
ok this already exists. Just exit the app without installing but still
return an ok result code so the chained applications can still install?