Hello Sandra,
I understand the inconvenience.
Please get into control panel "Uninstall Program" window and check whether you have other third party antivirus like Malwarebytes, Norton or McAfee installed on your PC.
If you find it please uninstall it and restart your PC and open AVG user interface. If it shows as passive mode click on "Fix now" to check what message it displays.
Please provide the screenshot of the message that appears after clicking on fix now to assist further.
To take a screenshot please follow the instructions mentioned in this link: http://avgread.me/1aZxsAV and attach the image to this post.
You can post the screenshot here in your topic. Click on 'Answer' & then click on the 'Image' [mountain symbol] & follow the instructions.