A client computer is connected via a network to an anti-virus server. A signal from the anti-virus server notifies the client computer that an anti-virus needs to be immediately downloaded from the anti-virus server. The client computer disengages from the network, and re-establishes a link with only the trusted anti-virus server. The anti-virus fix is installed, the client computer re-booted, and the client computer is then allowed to reconnect to the full network. If the client's primary operating system (OS) is infected, a secondary OS in the client computer performs the anti-virus download and execution. The disengagement from the network is performed by applying a filter in a network interface card (NIC) driver by the primary OS, the secondary OS, a service processor (SP), or by a virtual machine manager (VMM), depending on which is available at the client computer.