Here is a basic plan .
When installing a hard drive, partition it into C: and D: and put
the operating system and programs on C: and all of your data, e-mail
box, fax, Windows cab files/drivers and other data on the D: drive.
When it becomes necessary to upgrade your operating system or a do
totally new install, it is easier to format your C: and reinstall
everything without fear of losing your data. Installing peripherals
will be easier if you also have your drivers in a folder on the
D: drive as well.
More here >
http://www.aumha.org/a/parts.htm