This problem started with Chrome. The top menu became very large in size like someone lowered the resolution of their monitor which makes everything look bigger or set the DPI settings to high. I know I did neither. Then it happened to the Avast Secure Browser. And now Opera after the latest update.
The problem only seems to occur on the chromium based browsers. I was sure it wasn't a system setting, but more likely a startup switch off some kind. So I needed to go into the shortcut properties for my browser's.
The procedure is the same for all the browsers.
In my case I right clicked on the Opera icon on my taskbar. In the little pop up menu I clicked on Opera Browser and then Properties.
I went looking for something that I know not what and I found it. :-) I clicked around till I found what I was looking for. A setting I never noticed before, it's not in Windows 7.
On the Compatibility tab. towards the bottom, I clicked on the button Change high DPI settings. I knew I was on the right track but wasn't sure what the right settings should be so I just started clicking on different combinations and see if it fixed it.
I found the right combo. In the new window that opens when you click on the Change high DPI settings, towards the bottom where it says
High DPI scalling override
Check the box in front of Override high DPI scaling behavior. Scaling performed by:
In the drop down menu, it's probably set on Application, click on it and then click on System. Then OK. This box will close you can then click on Apply and OK in the Compatibility tab. And that did it.
If your shortcuts for your browser are on the desktop, then just right click on the shortcut and go to properties and follow through from there.
If your shortcuts are only in the Start menu then click on the start button. Then find your browser shortcut and right click on it. I used Avast Secure Browser for this example. Then click on More and the Open file location. This opens up the Start menu folder, find the shortcut you want, right click on it and go to properties and the procedure is the same from there.
Here is a before and after shot keeping in mind that in both cases the browser is opened up full screen.