Right-click the Start button, select "Device Management", "audio, video, games Controller".
Click the right button on "Realtek high definition audio device", property, driver, uninstall (so you delete the Realtek driver from your computer), restart.
Windows recognizes again Realtek, but uses the drivers that come with Windows.
Right-click the Start button, select "Device Management", "audio, video, games Controller".
Right button on "Realtek high definition audio device", property, driver, updates, "Search the driver on your computer", "pick from a list of drivers ...", select "High Definition Audio Device" (not realtek!) and go on.
Some menu items may be different in your language because I use Windows in Italian.
In this way the security banner will not appear, however, remember that you will not have an audio equalizer that came with Realtek audio driver.