Wi-Fi networks are prone to a large number of Denial of Service (DoS) attacks due to vulnerabilities at the MAC layer of 802.11 protocol. In this paper we focus on the De-authentication DoS attack in Wi-Fi networks. The impact of de-authentication DoS attack is severe as the victim gets disconnected from the network. This attack can be launched easily using minimal resources. In this paper we propose an Intrusion Detection System (IDS) along with Intrusion Prevention System (IPS) that not only detects the de-authentication DoS attack in a Wi-Fi network but also helps the victim station (STA) in recovering swiftly from the attack. Our proposed IDS is lightweight and detects the attack with high accuracy & low false positive rate. Our technique can be easily deployed on open as well as encrypted networks.