Apparently it is very simple, but I see that some people have trouble when it comes to set Opera default browser.
Compared to Firefox, Google Chrome, Safari si Internet Explorer, Opera has a little hidden option "Use Opera ace default web browser"And who did not set"default browser "for the first time and had the option"Do not show this dialog again”Checked, you will need to enter the Opera menu to set the browser default.
How do we set Oprea, default web browser.
1. Opera Menu (top left)> Settings > Preferences (or Ctrl+ F12 directly)
2. In the "Preferences" panel we go on the left menu to "Programs", and on the right we check "Check if Opera browser on startup is defalt".
Click OK.
When we reopen the browser we will be asked if we want to set Opera as the browser default. Click Yes.