Оформил: DeeCo
Автор: http://www.swissdelphicenter.ch

{ 
  Retrieves information about the time-out period associated 
  with the accessibility features. 
  The pvParam parameter must point to an ACCESSTIMEOUT 
  structure that receives the information. 
  Set the cbSize member of this structure and the 
  uiParam parameter to SizeOf(ACCESSTIMEOUT). 
}

 { 
  Ermittelt die maximale Zeit wo der Benutzer keine Eingaben macht bei den 
  Eingabehilfen. "uiParam" muss die Gro?e der Struktur 
  ACCESSTIMEOUT sein und "pvParam" muss eine ACCESSTIMEOUT-Struktur 
  ubergeben werden, die gefullt wird. 
}

 // ACCESSTIMEOUT structure 
type
   TAccessTimeOut = record
     cbSize: UINT;
     dwFlags: DWORD;
     iTimeOutMSec: DWORD;
   end;

 procedure GetAccessTimeOut(var bTimeOut: Boolean; var bFeedBack: Boolean;
   var iTimeOutTime: Integer);
   // bTimeOut: the time-out period for accessibility features. 
  // bFeedBack: the operating system plays a descending 
  //            siren sound when the time-out period elapses and the 
  //            Accessibility features are turned off. 
  // iTimeOutTime: Timeout in ms 
var
   AccessTimeOut: TAccessTimeOut;
 begin
   ZeroMemory(@AccessTimeOut, SizeOf(TAccessTimeOut));
   AccessTimeOut.cbSize := SizeOf(TAccessTimeOut);

   SystemParametersInfo(SPI_GETACCESSTIMEOUT, SizeOf(AccessTimeOut), @AccessTimeOut, 0);

   bTimeOut := (AccessTimeOut.dwFlags and ATF_TIMEOUTON) = ATF_TIMEOUTON;
   bFeedBack := (AccessTimeOut.dwFlags and ATF_ONOFFFEEDBACK) = ATF_ONOFFFEEDBACK;
   iTimeOutTime := AccessTimeOut.iTimeOutMSec;
 end;

 // Test it: 

procedure TForm1.Button2Click(Sender: TObject);
 var
   bTimeOut, bFeedBack: Boolean;
   iTimeOutTime: Integer;
 begin
   GetAccessTimeOut(bTimeOut, bFeedBack, iTimeOutTime);
   label1.Caption := IntToStr(Ord(bTimeOut));
   Label2.Caption := IntToStr(Ord(bFeedBack));
   Label3.Caption := IntToStr(iTimeOutTime);
 end;

 { 
  Sets the time-out period associated with the accessibility features. 
  The pvParam parameter must point to anACCESSTIMEOUT structure that 
  contains the new parameters. 
  Set the cbSize member of this structure and the uiParam 
  parameter to sizeof(ACCESSTIMEOUT). 
}

 { 
  Setzt Informationen zu den ACCESSEDTIMEOUT-Eigenschaften. 
  "uiParam" erwartet die Gro?e der ACCESSEDTIMEOUT-Struktur, 
  die in "pvParam" ubergeben werden muss. 
}

 procedure SetAccessTimeOut(bTimeOut, bFeedBack: Boolean; iTimeOutTime: Integer);
   // bTimeOut: If true, a time-out period has been set for accessibility features. 
  // bFeedBack: If true, the operating system plays a descending 
  //                    siren sound when the time-out period elapses and the 
  //                    accessibility features are turned off. 
  // iTimeOutTime: Timeout in ms 
var
   AccessTimeOut: TAccessTimeOut;
 begin
   ZeroMemory(@AccessTimeOut, SizeOf(TAccessTimeOut));
   AccessTimeOut.cbSize := SizeOf(TAccessTimeOut);

   case bTimeOut of
     True: AccessTimeOut.dwFlags  := ATF_TIMEOUTON;
     False: AccessTimeOut.dwFlags := 0;
   end;

   if bFeedBack then
     AccessTimeOut.dwFlags := AccessTimeOut.dwFlags or ATF_ONOFFFEEDBACK;

   AccessTimeOut.iTimeOutMSec := iTimeOutTime;

   SystemParametersInfo(SPI_SETACCESSTIMEOUT, SizeOf(AccessTimeOut),
     @AccessTimeOut, SPIF_UPDATEINIFILE or SPIF_SENDWININICHANGE);
 end;

 // Test it: 
procedure TForm1.Button1Click(Sender: TObject);
 begin
   SetAccessTimeOut(True, True, 600000); // 10 min. timeout 
end;