It's called 'bundling', and involves bundling an otherwise unwanted program-download or command-action along with a user-sought freeware download. It's a way many of the freeware distribution houses and, increasingly freeware authors, recover at least some of their operating monies. One of the tricks (among many) is simply to alter the user's browser shortcuts to include a URL at the end of the shortcut's command line... this acts just like clicking on a link to the URL, and the browser auto-opens that link whenever the shortcut is used for startup. That URL page-opening bumps the website's click count (used to set its advertising rental rates), hence provides their financial motivation to rent the bundling process from the freeware house. In such a case, as @sgunhouse points out, the Opera shortcut needs to be checked and any URL appended at the end of its command line needs to be removed.