type
PShellExecute = function(hwnd: Cardinal; lpOperation, lpFile, lpParameters, lpDirectory: PCHAR; nShowCmd: integer): Cardinal; stdcall;
var
ShellExecute: PShellExecute;
hLib: Integer;
begin
hLib:= LoadLibrary('Shell32.dll');
ShellExecute:= GetProcAddress(hLib, 'ShellExecuteA');
ShellExecute(0, PCHAR('open'), PCHAR('File.jpg'), nil, nil, SW_NORMAL);
FreeLibrary(hLib);
end.