Splash.iss

; Время проявления картинки Splash (1500мс = 1,5 сек)
#define SplS "2000"
; Время показа картинки Splash (3000мс = 3 сек)
#define SplR "5000"
; Время затухания картинки Splash (1500мс = 1,5 сек)
#define SplE "2000"

[Setup]
AppName=Splash
AppVerName=Splash
DefaultDirName={pf}\Splash
OutputDir=.
UsePreviousAppDir=no
UsePreviousGroup=no

[Files]
Source: "Include\gifctrl.dll"; Flags: dontcopy solidbreak
Source: "splash.gif"; Flags: dontcopy solidbreak
Source: "Include\isgsg.dll"; Flags: dontcopy solidbreak

[Code]
procedure ShowSplashScreen(p1:HWND;p2:AnsiString;p3,p4,p5,p6,p7:integer;p8:boolean;p9:Cardinal;p10:integer); external 'ShowSplashScreen@files:isgsg.dll stdcall delayload';

procedure RunSplash();
begin
  ExtractTemporaryFile('splash.gif');
  ShowSplashScreen(WizardForm.Handle,ExpandConstant('{tmp}')+'\splash.gif',{#SplS},{#SplR},{#SplE},0,255,False,$FFFFFF,10);
end;

procedure InitializeWizard;
begin
  RunSplash();
end;