1. A method, comprising: during an initial backup operation at a computer system: creating a backup virtual hard drive (VHD) of a data volume at a storage device of the computer system; creating a metadata VHD corresponding to the backup VHD; and transmitting the backup VHD to a remote storage location; after completion of the initial backup operation, detecting a change to a file of the data volume; creating a differential VHD based on the metadata VHD, wherein the differential VHD indicates the change to the file; updating the metadata VHD to reflect the change to the file; and during a subsequent backup operation at the computer system, transmitting a copy of the updated metadata VHD and the differential VHD to the remote storage location.