Article in English: Do this by double-clicking its icon in the desktop. Once Chrome is launched, click on the Options menu in the upper-right corner of the window. It is the icon with three horizontal lines stacked on top of each other. In the Options menu, scroll down and hover your mouse pointer over “Tools.” When the extended menu appears, click on “Extensions.” You can see which extensions are installed on your Chrome browser in this menu. Scroll through the list of extensions until you find an extension with AVG. Across the extension’s name are a check box and a trash icon. Click on the trash icon to delete the iSearch extension. Once the extension has been deleted, go back to the Options menu, but this time, click “Settings.” Under the Search header (just scroll a bit down the Settings page to find this), click on the small arrow pointing down. A list of search engines that you can use with Chrome will appear. Choose a search engine and click on it to set it as default. Simply restart the browser by closing it (pressing the red X at the top-right corner of the browser window) and launching it again.

Summary in Chinese:
打开谷歌Chrome。 点击选项菜单。 进入扩展程序。 找到iSearch AVG扩展程序。 删除iSearch AVG扩展程序。 前往设置菜单。 设置默认浏览器。 重启浏览器。