My laptop stopped recognizing my second monitor

[SCL22]

I have an HP Spectre x360, I've had a second monitor connected to it for months and it just stopped recognizing it. Cables all work. I've tried another laptop with it and the monitor works. I've shut it down and restarted it. I checked for driver updates for it  (it's a ViewSonic) which I clicked on and assume updated if there were any. My laptop won't detect it. Any advice would be much appreciated. Thank you.

[itsmyname]

@SCL22 -- if you hold-down the "Windows" key (bottom-left of your keyboard) and tap the "P" key, does it open a new window that lets you choose between the "internal" and the "external" display?

Within the Windows "Device Manager", and expand the "Display" section, does it list both displays?

[SCL22]

Thanks for responding! When i tap p, i have a project screen with pc screen only, duplicate, extend and second screen only. on the monitor question, only generic pnp monitor is there. 

[itsmyname]

@SCL22 --  i have a screen with PC screen only, duplicate, extend and second screen only.

What happens when you select "duplicate" ? Does the second monitor "wake-up" ?

Within the Windows "Device Manager", if you expand the "Monitors" section, how many entries are present?

[SCL22]

Hi. Nothing happens when I press duplicate and there's only one monitor listed -- Generic PnP Monitor

[itsmyname]

@SCL22 -- there's only one monitor listed -- Generic PnP Monitor

If you run the HP Support Assistant, does it locate, download, and install a "better" device-driver than what Windows provides in the "Display Adapter" section of the Windows "Device Manager" device-tree?

[SCL22]

Under the software and drivers tab, should i just check the boxes for updates? One is Select all and the other is +HP Notebook System BIOS update (Intel Processors)? When i first went into the HP Support Assistant it said there was one update which I did. Thank you again.