I am curently running NAV and AVG at the same time with NAV as the primary (scanning inbound stuff) and run a complete system scan once a week with both one after the other. IU ahvent had any problems with it. As far as system resources i havent had anyproblems with that either. Like pc cillin AVG can be kind of a pian in the butt at times but its still a good proggie and its free and updates ALOT more often than nortons