Detect if a part of the software is installed...

Hi All,

I'm currently working on three different programs, one of which will be included in the instalation package of the other two. What I mean is this:

A -> One stand-alone Software
B -> Another stand-alone software
C -> Yet another stand-alone software

Now, Product A's and Product B's installers will both include Product C as part of their installtion. What I want to do is for either setup program to check to see whether Product C has been previously installed, if not then install the software itself. They all use registry keys, so it's possible to detect them, but I don't know how. Is this whole idea possible to implement?

Please keep it as detailed and step-by-step as possible, since I'm very new to this. 🙂

Thanks.🙂

Installation of product C you can make using one hidden section (inside section include write in registry "installed-identification" ):

Section "-ProductC"

...

WriteRegStr "..root_key.." "..sub_key.." "..name.."

...

SectionEnd

In .onInit function you must detect if a product is already installed - read registry using ReadRegStr instruction. If value is present (product installed) -> disable ProductC section (use SetcionSetFlags). If value is absent -> enable this section.

And include these code for both installers scripts.