So, I uninstalled AVG, downloaded and ran their AVG Remover Tool ( reinstalled AVG, and immediately after the installation was complete I deactivated the Cache Server (open User Interface Cache Server).Also, make sure any previous antivirus software products are uninstalled, and that includes downloading and running the uninstall or removal tools for those software products (Query Store is not active for new databases by default.Execution plans for any specific query in SQL Server typically evolve over time due to a number of different reasons such as statistics changes, schema changes, creation/deletion of indexes, etc.Don't rely on any antivirus software's internal uninstaller to complete the job, because it usually doesn't; some small pieces of the software will often be left behind to possibly cause conflicts with your new antivirus software. On the Advanced Settings / Schedules / Definitions Update Schedule, the "Run Automatically" button is permanently checked, as well as the "Run when computer starts up if task has been missed" button. AVG Free antivirus automatically updates virus definitions and program update, they’re pre-configured in such a way in Settings.
Open AVG user interface, click Options Schedules, select’ Definition Update Schedule’ and uncheck ‘Enable this task’, click ‘OK’.
The SQL Server Query Store feature provides you with insight on query plan choice and performance.
It simplifies performance troubleshooting by helping you quickly find performance differences caused by query plan changes.
If you're running Vista or Windows 7, I've found Microsoft Security Essentials to be perfectly adequate.
If you installed AVG today, then what you are experiencing is not an update, but rather the Cache Server.