I have a laptop running Windows 7 and a desktop running XP. The laptop is backed-up using its own facility in ‘Maintenance’ while XP uses ATI9. Thank goodness I’ve never had to call on the back-ups on either machine. Would it be possible, theoretically, to wipe a drive clean, reformat it, and then install the back-ups kept on an external drive?
I've never used W7's backup so can't comment on that.
But using ATI (I use ATI8) to restore in XP is a doddle.
You do not need to wipe the drive partition beforehand as the image restore takes care of that.
I STRONGLY recommend that, if you have not already done so, you create an ATI emergency boot disk (CD) before doing anything else.
You can restore non-system partitions from within Windows. You can also kick off the restore of a system partition (i.e your C: drive) from within Windows and ATI will tell you that it needs to reboot to do the restore and will then boot into its own non-windows shell. Personally I always restore using the emergency boot disk (which also uses the non-windows shell) anyhow. A very good reason for creating the emergency boot disk is that if a restore of the system partition craps out part way through, you won't be able to try again without an emergency boot disk.
You can always go through the initial stages of setting up a restore without hitting confirm on the final screen. That will give you a feel for how it works.
In doing a restore you need to bear in mind that ALL of the information on the partition is overwritten (OS, PGMS, Documents etc. etc. etc.).