Hi
I have 2 internal 1 Terabyte hard drives divided into 4 partitions.
I have 3 external hard drives totaling 2.5 Terabytes (these are only turned on when I want to copy to or from them. Sometimes they aren't turned on for months. The are used only for additional backup.
Every thing that is important is backed up at least twice, some things 3 times, like my photos.
When I talk about data that I don't put on Drive C:\ I'm talking about Job Files, Music Files, Photographs, Program Installation files that I've downloaded and don't have disks for, backups of my Documents, favorites, etc.
Most of my games (which often don't need to be re-installed if Windows is re-installed), and some graphic arts software that had a lot of added content, like my 3D software which had many added mods etc. that would be lost if I had to reinstall it.
From experience I've learned what software needs to be installed if Windows is re-installed.
I.e. Photoshop always needs to be re-installed if Windows is, but Adobe Premiere doesn't.
So I install Photoshop on C:\ but I install Premiere on my Graphic Arts drive along with Fraps, Poser, and things like that.
Most games can be installed or copied anyplace and they will still run after a Windows reinstall, or even an upgrade, so they all go on my Games drive.
What I do put on C:\ is, Windows, all my installed software that would have to be re-installed if Windows is re-installed anyway, like Microsoft Office, Adobe Photoshop, Illustrator and InDesign etc.
Also my custom Windows sounds, icons etc, and desktop art, but these are also backed up elsewhere.
I don't put anything on C:\ that I'm worried about losing, if I had to format the drive.
Mike