The most common cause of arbitrarily closing the browser "Opera" - the viruses. Sometimes everything is solved by using a normal cleansing system anti-virus, and in some cases, for example when the virus affects the system files without possibility of recovery, you may need to reinstall the program.Download Cure It from the official website of Dr. Web based http://www.freedrweb.com/download+cureit/) and run a full scan of computer for viruses, including memory and boot sector. Next, run the database update your antivirus program and scan your computer again. Then try to start the browser "Opera" again.If after removing viruses from your computer, the browser will still close on their own without your involvement, then reinstall it. To do this, first run the uninstall from the menu "control panel" and then download the latest version from the website http://www.opera.com/. Install it and make any necessary adjustments. The parameters specify the dialog box before closing the "Opera". Note the download for your browser with additional plug – ins- many of them can be the reason for the closure of the program. Trust only verified developers and not download Addons from shady sites. Check that you are not running at the time you close your browser any unknown process in your system. To do this, open the task Manager and view the list of running programs and processes. If this problem occurs too often in your browser, try to use alternative browsers such as Mozilla Firefox (http://mozilla-russia.org/, Safari http://www.apple.com/ru/safari/download/) or any other. It is possible that the problem may lie precisely in the incompatibility of the "Opera" is installed on your computer by other software.