(continued)
The following screenshot was taken when my parallel XP installation was booted.

The Windows "Program Files" folder is on logical drive (G:) and serves both installations. Settings on logical drive (F:) contains the "Documents and Settings" folder for the Primary XP installation, and Settings on logical drive (S:) contains the "Documents and Settings" folder for the parallel XP installation. Note that (C:) changes from Root on the Primary XP installation to Boot on the parallel XP installation; the unloaded system drive becomes (D:) in both cases.
