How to detect and use separate Display p2719H

Hi - I ordered and received a Dell 27 inch monitor P2719H.  I plugged it into my Precision 7710 mobile workstation, trying the USB and then eventually the HDMI cords.  At some point one of them worked, but only for a bit, and eventually the project has descended into the monitor not detecting that it is hooked up to anything and power saving after 4 minutes. 

I downloaded something called Dell Display manager but it displays an error message and says please connect a supported Dell Monitor.

I have tried poking around in Windows and can't seem to find an area where I can ask the computer to detect a new display.

Have I maybe turned off some sort of plug-and-play aspect as a security measure so that's why it's not detected?  Any suggestions on how I can just get this to work?