Solved Win 8.1 laptop can't remember default browser?

I'm actually having a very odd problem...

I have an older laptop that I have updated to Win 8.1, installed drivers, etc.

At some point, 8.1 stopped remembering that Opera is my default browser and when an active hyperlink is clicked from a window (such as from Steam, Skype or other source) the notification pops up saying that a new app is available to open this link. It shows: IE, Chrome, and Firefox, and asks "How do you want to open this link?" it says: "Keep using Internet Explorer (Default)", "Open with Firefox" and "Open with Chrome."

From here, I am forced to go to the Opera shortcut that I have pinned to the start screen, and open the link from there, and the problem repeats each time I use a link. I have a habit of right-clicking links and sending them to new tabs in Opera, but when I do left-click, the notification that a new app is available to open this link and the option to select IE, Chrome and Firefox persists.

Obviously, I would like to move back into using Opera, but I can't get Win 8.1 to remember the browser. It is almost like Opera doesn't exist, except for the fact that it is visibly there.

is there a setting in Opera to set it as the default browser

Can you set your default browser in default programs?
Change which programs Windows uses by default - Windows Help

Check to make sure any toolbars, coupon stuffs, etc are uninstalled, and check for malware. If you'd like, malwarebytes (.org) has a free and paid version of a malware scanner that is highly praised for its effectiveness. Try it out if you need to scan your computer for baddies.

Three things fixed it;

First, associating .htm and .html protocols with the browser I want as default.
Second, selecting the "yes" option to the default browser question. (innocuous, I know.)
Third; Windows Update

its the browser not windows