add additional application in setup project (vb 2005)

Question

halo everyone...

I get problem in setup project. first In project I include other application initsystem, how the setup that i build find out the computer is have initsystem application? if the client computer have the initsystem setup will not installed twice, if not then setup will installed.

the second one, initsystem is additional program that support the main application. in this project i have 5 additional program. the question is how make setup that user can select and install the selected additional program during installation?

please help me.