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Do you mean it doesn't show to those 2 devices at the same time? It cannot do that. Each device must have a separate and diff type port to use. That's not available on a 10 yr old Vostro. You can only have one external monitor or device. Projectors require special steps--see:

https://projectortop.com/how-to-connect-laptop-to-projector-with-hdmi/

Thank you for the speedy reply.

When I connect the HDMI cable from the Vostro 3350 to either the DELL Projector  or the Samsung 24 inch  monitor i get a "No signal message" whereas, using the same cable connecting the Vostro  to the TV HDMI port works fine.

If there is more than one input on the Samsung monitor, you may need to select an input if it does not  do so automatically.

Thank you for the reply.

The Samsung Monitor has a single  VGA and  a single HDMI port which are toggle switchable with a mode switch.

The VGA port is connected to my Dell desktop and works fine.  But even disconnecting the VGA, and connecting the HDMI and toggling the mode switch to HDMI only results i the " no signal"  message

selecting dual or external monitor from the LapTop has no effect either.

One might be excused for thinking that it is the monitor that is at fault.