diff --git a/Components/TaskbarProgressFunc.pas b/Components/TaskbarProgressFunc.pas
index cb988d79..3de90c54 100644
--- a/Components/TaskbarProgressFunc.pas
+++ b/Components/TaskbarProgressFunc.pas
@@ -48,14 +48,16 @@ procedure SetAppTaskbarProgressState(const State: TTaskbarProgressState);
   StateFlags: array[TTaskbarProgressState] of Integer = (
     TBPF_NOPROGRESS, TBPF_INDETERMINATE, TBPF_NORMAL, TBPF_ERROR, TBPF_PAUSED);
 begin
-  if InitializeTaskbarList then
-    TaskbarListInterface.SetProgressState(Application.Handle, StateFlags[State]);
+  if InitializeTaskbarList and Assigned(Application.MainForm) and
+     Application.MainForm.HandleAllocated then
+    TaskbarListInterface.SetProgressState(Application.MainForm.Handle, StateFlags[State]);
 end;
 
 procedure SetAppTaskbarProgressValue(const Completed, Total: Cardinal);
 begin
-  if InitializeTaskbarList then
-    TaskbarListInterface.SetProgressValue(Application.Handle, Completed, Total);
+  if InitializeTaskbarList and Assigned(Application.MainForm) and
+     Application.MainForm.HandleAllocated then
+    TaskbarListInterface.SetProgressValue(Application.MainForm.Handle, Completed, Total);
 end;
 
 end.
diff --git a/Projects/Src/Setup.MainFunc.pas b/Projects/Src/Setup.MainFunc.pas
index bbc4380c..c30616ad 100644
--- a/Projects/Src/Setup.MainFunc.pas
+++ b/Projects/Src/Setup.MainFunc.pas
@@ -2389,14 +2389,6 @@ procedure RestartComputerFromThisProcess;
   RestartInitiatedByThisProcess := True;
   { Note: Depending on the OS, RestartComputer may not return if successful }
   if not RestartComputer then begin
-    { Hack for when called from RespawnSetupElevated: re-show the
-      application's taskbar button } 
-    ShowWindow(Application.Handle, SW_SHOW);
-    { If another app denied the shutdown, we probably lost the foreground;
-      try to take it back. (Note: Application.BringToFront can't be used
-      because we have no visible forms, and MB_SETFOREGROUND doesn't make
-      the app's taskbar button blink.) }
-    SetForegroundWindow(Application.Handle);
     LoggedMsgBox(SetupMessages[msgErrorRestartingComputer], '', mbError,
       MB_OK, True, IDOK);
   end;
@@ -2415,9 +2407,6 @@ procedure RespawnSetupElevated(const AParams: String);
     NotifyNewLanguage: Integer;
   end;
 begin
-  { Hide the taskbar button }
-  SetWindowPos(Application.Handle, 0, 0, 0, 0, 0, SWP_NOSIZE or
-    SWP_NOMOVE or SWP_NOZORDER or SWP_NOACTIVATE or SWP_HIDEWINDOW);
   Cancelled := False;
   try
     Server := TSpawnServer.Create;
@@ -2438,11 +2427,8 @@ procedure RespawnSetupElevated(const AParams: String);
     { If the user clicked Cancel on the dialog, halt with special exit code }
     if ExceptObject is EAbort then
       Cancelled := True
-    else begin
-      { Otherwise, re-show the taskbar button and re-raise }
-      ShowWindow(Application.Handle, SW_SHOW);
+    else
       raise;
-    end;
   end;
   if Cancelled then
     Halt(ecCancelledBeforeInstall);
@@ -2461,7 +2447,6 @@ procedure RespawnSetupElevated(const AParams: String);
     except
       { In the unlikely event that something above raises an exception, handle
         it here so the right exit code will still be returned below }
-      ShowWindow(Application.Handle, SW_SHOW);
       Application.HandleException(nil);
     end;
   end;
diff --git a/Projects/Src/Setup.RegSvr.pas b/Projects/Src/Setup.RegSvr.pas
index ed155905..a2e41f49 100644
--- a/Projects/Src/Setup.RegSvr.pas
+++ b/Projects/Src/Setup.RegSvr.pas
@@ -119,9 +119,7 @@ procedure RunRegSvr;
 
   { Set default title; it's set again below after the messages are read }
   Application.Title := 'Setup';
-  { This is needed for D3+: Must force the application window visible since
-    we aren't displaying any forms }
-  ShowWindow(Application.Handle, SW_SHOW);
+  Application.MainFormOnTaskBar := True;
 
   InitializeCommonVars;
 
@@ -133,7 +131,6 @@ procedure RunRegSvr;
     registry entries be in an incomplete/inconsistent state? I'm not sure, so
     a mutex is used here to ensure registrations are serialized. }
   Mutex := Windows.CreateMutex(nil, False, 'Inno-Setup-RegSvr-Mutex');
-  ShowWindow(Application.Handle, SW_HIDE);  { hide taskbar button while waiting }
   if Mutex <> 0 then begin
     { Even though we have no visible windows, process messages while waiting
       so Windows doesn't think we're hung }
@@ -142,7 +139,6 @@ procedure RunRegSvr;
     until MsgWaitForMultipleObjects(1, Mutex, False, INFINITE,
       QS_ALLINPUT) <> WAIT_OBJECT_0+1;
   end;
-  ShowWindow(Application.Handle, SW_SHOW);
   try
     MsgFilename := PathChangeExt(NewParamStr(0), '.msg');
     ListFilename := PathChangeExt(NewParamStr(0), '.lst');
diff --git a/Projects/Src/Setup.Uninstall.pas b/Projects/Src/Setup.Uninstall.pas
index 26bdb54e..a01ad046 100644
--- a/Projects/Src/Setup.Uninstall.pas
+++ b/Projects/Src/Setup.Uninstall.pas
@@ -349,19 +349,9 @@ function RespawnFirstPhaseIfNeeded: Boolean;
   RequireAdmin := (ufAdminInstalled in Flags) or (ufPowerUserInstalled in Flags);
 
   if NeedToRespawnSelfElevated(RequireAdmin, False) then begin
-    { Hide the taskbar button }
-    SetWindowPos(Application.Handle, 0, 0, 0, 0, 0, SWP_NOSIZE or
-      SWP_NOMOVE or SWP_NOZORDER or SWP_NOACTIVATE or SWP_HIDEWINDOW);
-    try
-      RespawnSelfElevated(UninstExeFilename,
-        Format('/INITPROCWND=$%x ', [Application.Handle]) + GetCmdTail,
-        UninstallExitCode);
-    except
-      { Re-show the taskbar button and re-raise }
-      if not(ExceptObject is EAbort) then
-        ShowWindow(Application.Handle, SW_SHOW);
-      raise;
-    end;
+    RespawnSelfElevated(UninstExeFilename,
+      Format('/INITPROCWND=$%x ', [Application.Handle]) + GetCmdTail,
+      UninstallExitCode);
     Result := True;
   end;
 end;
@@ -402,11 +392,6 @@ procedure RunFirstPhase;
   Longint(OldWindowProc) := SetWindowLong(Wnd, GWL_WNDPROC,
     Longint(@FirstPhaseWindowProc));
   try
-    { Hide the application window so that we don't end up with two taskbar
-      buttons once the second phase starts }
-    SetWindowPos(Application.Handle, 0, 0, 0, 0, 0, SWP_NOSIZE or
-      SWP_NOMOVE or SWP_NOZORDER or SWP_NOACTIVATE or SWP_HIDEWINDOW);
-
     { Execute the copy of itself ("second phase") }
     ProcessHandle := Exec(TempFile, Format('/SECONDPHASE="%s" /FIRSTPHASEWND=$%x ',
       [NewParamStr(0), Wnd]) + GetCmdTail);
@@ -733,11 +718,6 @@ procedure RunSecondPhase;
       Log('Restarting Windows.');
       RestartInitiatedByThisProcess := True;
       if not RestartComputer then begin
-        { If another app denied the shutdown, we probably lost the foreground;
-          try to take it back. (Note: Application.BringToFront can't be used
-          because we have no visible forms, and MB_SETFOREGROUND doesn't make
-          the app's taskbar button blink.) }
-        SetForegroundWindow(Application.Handle);
         LoggedAppMessageBox(PChar(SetupMessages[msgErrorRestartingComputer]),
           PChar(SetupMessages[msgErrorTitle]), MB_OK or MB_ICONEXCLAMATION,
           True, IDOK);