check mo startup mo, its probable na may isang file dun na nagpopoint dyan sa adware na yan
OR, kung limited to browser lang siya, may mga ibang adware na meron naiiwan na mga remnants kahit uninstall mo na siya. complete removal will depend on what browser is used. pero it might be easier to just use some adware cleaner tool/s (i.e. adwcleaner, junkcleaner, etc etc)