(H1) Nodes out side the network enter the computer network with the amount A. Every node in the state (S), (L), (I) or (R) leaves the network, without connecting with others node, with the same rate µ. The total number of nodes N(t) is constant, that is N(t) = N, ∀t. (H2) Every susceptible node is transferred to latent state with probability v(t) = λL(t). (H3) Every latent node becomes infected node with constant rate γ, infected node becomes recovered node with constant rate α by using effective anti-virus program. (H4) Each infected node returns susceptible state, by reinstall the system or other means, with constant rate ω. Latent node becomes recovered node, by using antivirus program, with constant rate δ. (H5) Due to antidote, every susceptible node acquires temporary immunity with constant rate ε. For system vulnerability, we assume that ε < µ.