Probe for Clocks

   The Probe for Clocks screen prompts you to allow
   the installation program to detect what video
   modes your video card and monitor are capable of
   using.
   
   You should select Probe for best results. By
   allowing the installation program to detect these
   modes for you, your choices for video modes may be
   narrowed down based on your video card and monitor
   capabilities.
   
   However, if a previous attempt to probe video
   modes ended with a bad result (such as having to
   reboot your system), you should choose Skip and
   then choose your preferred video modes.