Here's how to turn off the green border in the web-browser, step-by-step:
Open the ESET user interface from the system tray notification area.
Press the F5 key to open the Advanced setup view.
In the left navigation pane, select the Web and email option. The option will expand.
Below Web and email, select the Banking & Payment protection. The right pane will show the Basic view of its settings.
In the right panel, scroll down (if needed) until you see the option named Browser's green frame and toggle it.
Click on the 🛡OK button at the bottom of the window
At that point, browser windows should no longer open with the green border. Depending upon your version of Microsoft Windows and of the web browser(s), it is possible the web browser(s) may need to be restarted.
ThommyBoy gave kudos to Aryeh Goretsky in How to remove green border from Google Chrome tabs?
