1. A method for updating offline virtual machines, the method comprising: mounting an image of an offline virtual machine on a host operating system; generating drive-mapping information for the mounted virtual machine image; loading registry information of the mounted virtual machine image onto the host operating system using the drive-mapping information; determining an update to be applied to the offline virtual machine based on the registry information; retrieving a patch bundle based on the determination, wherein the patch bundle comprises registry update instructions, file system update instructions, and a patch file; and executing the patch bundle on the host operating system to update the offline virtual machine.