Cuperman and Landau (1974) have analytically investigated the modifications of parallel propagating whistler waves in an infinite uniform warm (w) anisotropic plasma in the presence of various amounts of cold (c) plasma. The authors found that the addition of cold plasma increases the instability range in k space and increases (decreases) the maximum rate of growth if P≡&bgr;A (A+1)21). Here &bgr;≡4&pgr;n&ohgr;KT∥,&ohgr;/B20 and A≡ (T⊥/T∥)&ohgr;-1. Cuperman et al. (1973) have performed a computer simulation experiment and confirmed the analytical predictions for the case P>1. This paper presents the results of a computer simulation for the regime P≪1. The analysis of the time behavior of the total electromagnetic activity developed confirms the basis analytical predictions for the possible enhancements of the whistler mode instability in the presence of cold plasma.