A client quarantine agent requests bill of health from a quarantine server, and receives a manifest of checks that the client computer must perform. The quarantine agent then sends a status report on the checks back to the quarantine server. If the client computer is in a valid security state, the bill of health is issued to the client. If the client computer is in an invalid state, the client is directed to install the appropriate software/patches to achieve a valid state. When a client requests the use of network resources from a network administrator, the network administrator requests the client's bill of health. If the bill of health is valid, the client is admitted to the network. If the bill of health is invalid, the client is placed in quarantine.