The restore strategy that computer companies use has changed over the
years and to some extent differ with each company. Originally users
would have to reinstall the OS completely, then install the
applications, those that came with the machine and those that they had
installed since they got the machine.

My Sony PII had a editable text file that provided the information
necessary to install the 'pre-installed' applications. Soon after I
got my computer I investigated this file and tried to edit out the
applications that I did not want installed.
The references to each program were coded rather than mentioning the
program name, so I clicked on each file to find out which program it
was. I then make a list the programs I wanted and those not. I think
that I ended up just manually installing each program. Then I used
Norton Ghost to clone my C partition. I have followed some version of
this strategy ever since.

As time went buy computer companies started to provide what they
called 'recovery' disks or disk sets. The bean counters must have had
a fit so that companies began creating recover partition with all the
install programs on them. I did not realize that this was the way my
brother's computer was set up and I accidentally wiped the recover
partition on his computer. We contacted HP and got install disks.

My most recent PC, a Dell, came with a combination of an a recovery
disk and files on the hard drive, mostly drivers and a few apps. But
these also used code numbers instead of name, so I investigate the
files an and renamed them. The install disk installed mostly the OS.
So after running it I had to install the drivers and the few pre-
installed programs.
Actually have to admit that I goofed on this machine, it too had a
recovery partition that I managed to damage. "That's what you get for
tampering!" That's true, but that is how I learn about computers. In
fact that is how I have learned about most technology. That's what I
am, a technology buff. And I still use Ghost to clone my C partition
to another partition. These days with huge hard drives this is easy.
As for my data files, each of my computers had pretty much the same
partitions, Audio Video files, Archived program files, personal data
files and Computing related files.

The result is that my files exist in duplicate. In addition the same
partitions exist on my external hard drive.
My External has two partitions, one for my PCs, one for my Macs. Mac
Leopard now has a program called Time Machine, a back up program par
excel-lance. Well that's what they say, I have not tried to do a
restore with TM yet.