Security is provided for a client by replacing a volume boot module adapted to execute during a boot process of the client with a repair module. The client is booted to start the boot process and to execute a master boot module. The repair module is executed in place of the volume boot module. The repair module determines whether the master boot module is infected with malware. If the master boot module is infected, the repair module repairs the malware infection by disabling and/or removing the malware.