To go back from external monitor on a laptop you have normally to choose the "escape" button on your keyboard. Did you try?

No, I hard rebooted without trying obvious solutions and made a forum thread with a problem.
Then I sarcastically replyed to the question about the obvious solution.

First, make sure you are on the latest version of Vegas 15, second make sure your video card drivers are updated. Next, remember we are all just users and can't read minds, so sarcasm is not the best way to get results.

Check.

Check.

You might have a point, after all it's the internet, we have to assume we are dealing with idiots in the frist place and ask obvious questions to determine if they are idiots, or easily annoyed people.

we have to assume we are dealing with idiots in the frist place and ask obvious questions to determine if they are idiots,.....

And lucky enough those idiots are able to ignore the forum members they don't like.

😇

Great, one less. Now, can we get back to the matter of this thread...

I've had multiple issues with secondary preview in Windows 10.

1. Usually the first I time turn in on in Vegas I can no longer do anything in Vegas and I have to restart then it works.

2. Many times Vegas gets confused which of my two monitors is monitor 1 or 2. What windows identifies as monitor 1 Vegas sometimes thinks is monitor 2.

3. Many basic editing functions while using secondary preview cause both screens to temporarily flash to black which is really annoying.

All of these problems began for me in Windows 10. Windows 7 worked fine. I'm using a Radeon RX 480 with 8gb built in memory.

Well, I have it worse, the secondary monitor turns black, coursor doesn't move, keys don't do anything, Esc (obviously) has no effect, even ctrl+alt+delete cannot do the trick, only hard reboot. And then the situation is all over again. So I'm left with with a small preview windows with 3x3 tiled multicams where I see even less, and even less with quality settings to have smooth playback (Draft-Quarter), because they have to be 2x2 and 3x3, rather than 3x2 for example, as I have max of 5 to 6 shots...

I searched for your system as described, HP HDX 18. Is this the laptop youare using?

If I was sarcastic I'd say, that I use it as my lap heater.

But let's pretend that I'm not and I will just answer your question. Yes I do use this model.

And how is your external monitor connected?

With a VGA cable.

I'll share this anecdote from the 1990's.

I created an AutoCAD drawing for a data center upgrade. At the time, almost no one on the planet used pdf files to send e-paper to people involved in big projects. It has since become the de facto standard. I actually spent ~$250 of my own money for the full Adobe Acrobat application so I could communicate graphically with all the team members without having to stand over a plotter all day, every day. My drawings were complex with tens of thousands of entities and much of that detail made it into the pdf files that I sent.

One morning, I sent a pdf to the network supervisor who was responsible for executing part of the plan. Immediately after hitting the send button, I received a call from the network supervisor who complained that something in my attachment broke his machine. His screen went black and the system was unresponsive. Incredulous, I walked downstairs to speak to him in person. By the time he explained what had happened, the system started to draw some of the objects on the screen.

Don't mistake this parable for sarcasm.

Two things happened as a result of that experience. 1) I began to flatten my pdf files to accommodate the hardware of my audience and 2) The network group used this example as a justification to upgrade their PCs from the 486 processors that were common at the time.

I would try the HDMI port. I had a Dell laptop from that era and it actually was a hybrid GPU, a "build in" together with a dedicated one. The build in would be the VGA port and laptop display and the dedicated one was on the HDMI port only. If yours is similar, Vegas may have a problem seeing the "external" monitor correctly.

Interesting story, I fail to see the analogy, let's blame the language barrier for that.

I would try the HDMI port. I had a Dell laptop from that era and it actually was a hybrid GPU, a "build in" together with a dedicated one. The build in would be the VGA port and laptop display and the dedicated one was on the HDMI port only. If yours is similar, Vegas may have a problem seeing the "external" monitor correctly.

The only HDMI-compliant device I have is Ninja2, not very helpful.

I would try the HDMI port. I had a Dell laptop from that era and it actually was a hybrid GPU, a "build in" together with a dedicated one. The build in would be the VGA port and laptop display and the dedicated one was on the HDMI port only. If yours is similar, Vegas may have a problem seeing the "external" monitor correctly.

The only HDMI-compliant device I have is Ninja2, not very helpful.

Well, should work for testing? The Ninja2 should be able to display the output. If that works, you may need a HDMI to VGA adapter to get things going, provided you don't want to change your external monitor.

It might be worth a try, I guess.

I definitely will be going to get a better secondary monitor, though I guess I should hunt a faster computer first.

Well, that's a tough one. You may be able to utilize the laptop a bit longer by using proxies but it's always good "see" what you are doing... that all depends if you can get the preview going at all.

I'll try the HDMI approach on a Ninja and I'll see.

Well, HDX was the top model back when it was released, it's amazing mine survived that long.

Maybe you did see the analogy after all, albeit belatedly/subconsciously.

Better equipment, I know.
But I am searching for a soluition with current gear.