Inno Setup Execute a batch file before [Files] section

Question

Currently my batch file is in [Run] section. I need my batch file to execute before the [Files] section. Is there a way to do this in Inno Setup? Currently the [Run] section

Answer 1

Continuing Deanna's great answer, code example:

[code]
function PrepareToInstall(var NeedsRestart: Boolean): String;
var
   ResultCode: integer;
begin
   Exec(ExpandConstant('{app}\serviceDeployment\unInstallService.bat'), '', '', SW_SHOW, ewWaitUntilTerminated, ResultCode)
end;

this code always returns an empty string, which tells the setup to continue. In case you want to stop setup (in some error cases) you need to return a non empty string and it will be displayed to the user (and setup will be stopped).

In order to return an error string add this line in PrepareToInstall's:

Result := 'Your Error Description';