From O&O Software:
O&O DiskImage lets you backup an entire computer or individual drives and files whenever you want even while the computer’s being used. Never again will you have to worry about lost data: The backups you make can be restored with just a few clicks of the mouse even if Windows is unable to start.
O&O DiskImage combines features for both the home user and the IT expert in one single product. A whole range of default and user-defined options lets you create the backup scenario that suits you best. And no with DiskImage To Go, you can create a USB or external disk with both a copy of your PC AND a boot medium.