A:AnswerDo you have the usb network adaptor that came with the HP connected? If so and it's still not working, you may need to purchase a stronger network adaptor.
A:AnswerYou can buy an adapter that connects to a usb drive and has 2 hdmi ports. Another alternative is to buy a VGA to HDMI adapter and plug the adapter into your VGA port giving you another HDMI connector. These solutions are inexpensive, and be be purchased for around 50 dollars.
A:AnswerThis PC will only accept 2 as it comes from the factory. I haven't opened mine, but I assume if you add a dual monitor card, you might be able to add a third?