Writing 32/64-bit specific registry key at the end of the installation in Inno Setup

Question

I want to create an installer with Inno Setup, my first time using this tool.
What I’m trying to do is wrapping an existing installer of an existing software with a more

Answer 1

To execute a code after an installation finishes, use the CurStepChanged event function and check for CurStep = ssPostInstall.

As Inno Setup is 32-bit application, by default it automatically gets redirected to the Wow6432Node on 64-bit systems. No need to do that explicitly. So if the Wow6432Node is the only difference between the 32-bit and 64-bit path, you do not to do anything special:

procedure CurStepChanged(CurStep: TSetupStep);
begin
  if CurStep = ssPostInstall then
  begin
    Log('Installation finished, writing connection string');
    RegWriteStringValue(
      HKEY_LOCAL_MACHINE, 'SOFTWARE\A', 'ConnectionString', 'Data Source=Test;');
  end;
end;

Of course, unless you use 64-bit installation mode.

See also: Writing 32/64-bit specific registry key in Inno Setup.

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If the key path really differs, use the IsWin64 function:

procedure CurStepChanged(CurStep: TSetupStep);
begin
  if CurStep = ssPostInstall then
  begin
    if IsWin64 then
    begin
      Log('Installation finished, writing 64-bit connection string');
      RegWriteStringValue(
        HKEY_LOCAL_MACHINE, 'SOFTWARE\A', 'ConnectionString', 'Data Source=Test;');
    end
      else
    begin
      Log('Installation finished, writing 32-bit connection string');
      RegWriteStringValue(
        HKEY_LOCAL_MACHINE, 'SOFTWARE\B', 'ConnectionString', 'Data Source=Test;');
    end;
  end;
end;