I have a stack of backup drives on the shelf with lots of copies of my legacy stuff (data, pictures music video etc) that is static and I keep that on different drives than my system drive (C:). Even on my laptops with only one physical drive I have 2 partitions, one for the system(C:) and D: for my data. You can use a simply "copy" for data but you pretty much need a drive image to rebuild the partition with the installed software, registry etc so I keep that as small as possible to reduce that image size. Also make sure your products use a library or documents folder on your D:.
I actually have six partitions on this machine spread out over 4 physical drives (one SSD for the system partition and a work space partition, 2 are mirrored for backup and a data drive with 3 partitions)
There is a great program called (Latshaw) file synchronizer that keeps your data partition backups current. It just compares your backup drive to your active drive and the program synchronizes them only updating the things that changed.
