When do data on Q: and S: change so that I need to backup?

[nuspieds]

At the end of every week I make drive image backups of my entire W700 system, so that means drives C:, Q: and S:.

But under what circumstances do the contents on Q: and S: get updated/written to? Only if I run TVSU? I'm trying to reduce the time it takes to do all the drive images and storage requirements. If Q: and S: are never being changed or if it is only when I run TVSU, then I would not need to image Q: and S: on a weekly basis, which would save time and space.

If you can shed some light on this, I'd greatly apprecicate it. Thanks!