Some of the issues: Media, software, techniques, restoring, online, relational database, bootable drive partitions, full, incremental, disk to disk (all internal, on same computer or a different one), disk to removable media, speed.
Backup to where? To a file on another disk in the same computer, on another computer, to removable media?
I'm running Windows XP SP3 and finally figured out how to use its NTBACKUP to get a copy of a bootable partition and how to restore it. Lesson: Likely need to practice and then take own, clear notes on the details. I wrote some scripts.
The removable media I've been using is just DVDs, and they top out at about 4 GB per DVD. For 20 GB, 200 GB, 1 TB, etc, 4 GB DVDs are a bummer.
I haven't tried double sided DVDs or BluRay. There is the old 'linear tape open' LTO option with about 1 TB per tape, but the drives, and likely the tapes, are expensive, and I know nothing ahout the software available.
Another option is to get a maybe 2 TB external hard disk connected via USB, but, again, I know nothing about the available software, if can do a 'synchronization', etc.
Now if you create the image, storing it on a high capacity network drive would be a good option since it allows you to retrieve multiple images from one location to perform a remote restoration.
The benefits of this method allow you to back up multiple drive images, and deploy functioning computers much quicker than reformatting a hard drive, downloading and installing each hardware driver.
At one company I worked for, we serviced 10 different desktop models. In addition to having a lot of DVDs, we also had each image stored on the network. So if Windows shit the bed, we'd say a short prayer that they were saving to their home folder on the DC like they're supposed to and send a signal to perform a network boot and restore the latest image for their model computer.