Certain aspects of a method and system for securing an operating system are disclosed. Aspects of one method may include receiving quarantine information of an operating system prior to booting the operating system. A quarantine mechanism may be enforced based on the received quarantine information prior to booting the operating system. At the time of boot up, the pre-OS quarantine agent may provide quarantine information to the quarantine server. The quarantine server may provide quarantine related information such as OS image to boot and network resources that may be accessed by the pre-OS quarantine agent. The pre-OS quarantine agent may perform the loading of the OS image based on the health and response from the quarantine server.