(continued)
The following screenshot was taken when my parallel XP installation was booted.
The Windows "Program Files" folder was on logical drive (G:) and served both installations. Settings on logical drive (F:) contained the "Documents and Settings" folder for the Primary XP installation, and Settings on logical drive (S:) contained the "Documents and Settings" folder for the parallel XP installation. Note that (C:) changed from "Root" on the Primary XP installation to "Boot" on the parallel XP installation; the unloaded system drive became (D:) in both cases.