How Do I Get To Safe Mode

I have a Dell Vostro 420 with the Windows XP Pro Downgrade option. When it boots up, I have XP Pro.

When I boot the computer and press F8 I get a screen that says

Windows Boot Manager
Choose an operating system to start or press Tab to select a tool

Operating System
Windows Vista

Tools
Windows Memory Diagnostic

OK so how do I get to Safe Mode?