Windows: how do I make Opera the default browser?

Question

How do I make the Opera web browser the default browser (Microsoft Windows)?

Preferably from within the browser itself.

E.g. such that this will open in Opera when in a BAT file or from the command line (cmd.exe):

start http://superuser.com/users/517/peter-mortensen

Answer 1

Preferences -> Advanced tab -> Programs -> check "Check if Opera is default browser on startup"

Then restart Opera, and select "Yes" in the dialog box that comes.

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Alternative is Windows Control Panel -> Default programs -> Set your default programs -> Opera Web Browser -> Set this program as default.