Hi !
How do I replace a file in the "_inst32i.ex_" file ? this file is extracted when I run setup.exe.

If you want to patch an installshield installation program, then you shouldn't try and modify any of the exe's or dll's. Instead look at the INS file and decompile that (with the various installshield decompilers around)

Don't mess with that file. What you will always be after are the files
with *.z *.cab *.hdr *.ins.