Gamer mode is a feature in ESET Windows home products:

• Activates by default when ESET detects any full screen application in use (games, movies, etc.)
• Maximizes performance and minimizes intrusion when full screen applications are running
• Postpones scheduled tasks (for example, modules updates or scheduled computer scans)
• Disables notification windows
• Minimizes CPU usage by ESET to improve system performance