Voting algorithms have been widely used in the realization of fault-tolerant systems. We introduce a new algorithm of software voting termed as adaptive majority voter. It uses the history of modules of a N-Modular Redundant (NMR) system to select the result of the most reliable module if it contributes toward a majority consensus. Furthermore, a new method for on-line creation of a history record of modules in a Triple Modular Redundant, TMR, system is proposed.The history vector of modules are not only used to improve the behavior of a wide range of traditional voters, but also can be used to identify the most erroneous/faulty modules of a system to take appropriate reconfiguration or damage preventive strategies. The empirical results show that the novel 'adaptive majority voter' has higher safety and availability levels than the traditional majority voter.