hi all thank you geezery and Inferi0r for ur suggestions and ideas for my query. well i wanted to ask 1 more thing, before that please have a look at the following file structure. Files pattern: A.exe - This file is the main file. b.exe - This is the file which is installed on the target computer if the user opens A.exe file. c.dll - This is the supporting file , which is also installed on the target computer if the user opens A.exe file Now, i have a file its a "A.exe" file which, when opened installs two files one is "b.exe" and another is "c.dll". so what i wanted was to take the first file "A.exe" into inno setup, make it run as the main executable file, this way it will install "b.exe" and "c.dll" file. And make the file "b.exe" start, at the startup from registry. now my question to you is, does my idiotic genius plan work? regards,