Inno Setup - Running script does not work in the first attempt for a new machine

Question

I have created a simple executable (.exe) file using Inno Setup Compiler 6.0.2 for installing a Windows application.

The .exe file calls a vbscript "Setup.vbs" that unzips "Application.zip" file and updates environment variables.

When I run the .exe file for the first time on a new machine, the .vbs file doesn't get executed. But, from second attempt onwards it works fine. Is this a known issue or is there any solution for this?

Here is the code snippet that I am using to call run .vbs file

[Code]
function PrepareToInstall(var NeedsRestart: Boolean): String;
    var ResultCode: integer;
begin
    ShellExec('',ExpandConstant('{app}\{#MyAppExeName}'), '', '', SW_SHOW, ewWaitUntilTerminated, ResultCode)
end;

Update

I want the .vbs to execute before the installation. So, I tried ExtractTemporaryFile, still I am facing the same issue. Not sure what is is wrong with the code below.

#define MyAppExeName "Setup.vbs"

[Files]
Source: "..\Application\Installation_Setup\Setup.vbs"; DestDir: "{app}"; Flags: ignoreversion

[Code]
function PrepareToInstall(var NeedsRestart: Boolean): String;
var
  ResultCode: integer;
begin
  ExtractTemporaryFile('{#MyAppExeName}');
  ShellExec('',ExpandConstant('{app}\{#MyAppExeName}'), '', '', SW_SHOW, ewWaitUntilTerminated, ResultCode)
end;

Thanks Andrew ! Being new to stackoverflow, having tough time posting code in comments. — Roshan Shiveshwar

Martin Prikryl Martin Prikryl · Accepted Answer · 2019-06-10T06:12:48

PrepareToInstall happens before installation. As you execute a file that is installed, it does not exist yet at the time you call it.

Possible solutions

Execute the script after installation from CurStepChanged(ssPostInstall):
Code to run after all files are installed

Or you can use [Run] section:
Executing installed batch file in Inno Setup
If you need to execute the script before installation (I do not think that's your case), use ExtractTemporaryFile.
For extracting ZIP, you do not need VBS script, you can do that directly from Inno Setup code.
How to get Inno Setup to unzip a file it installed (all as part of the one installation process)

Inno Setup - Running script does not work in the first attempt for a new machine

Update

1 Answers