This is a small list of folders and files which were displayed by the method mentioned on the previous post in this series.
Recycler : Recycler is aanother form of Recycle Bin. The Recycler folder contains a Recycle Bin for each user that logs on to the computer, sorted by their security identifier (SID).
System Volume Information : This contains the log files and backups of important System Files that are used for System Restore in Windows. (System Restore allows you to roll back all the settings and System Files to a previous time)
MSOCache : MSOCache is the folder that contains cached Office installation files. The folder is safe to delete.
NTLDR : This is the Windows NT boot loader. This is replaced by winload and Windows Boot Manager in Windows Vista
NTDETECT.COM : This file is used by Windows NT during startup to detect basic hardware required to boot the OS. This is used for Systems having BIOS.
Autoexec.bat : is most often used to set environment variables such as keyboard, soundcard, printer, and temporary file locations. It is also used to initiate low level system utilities.
These are the main folders and files in XP.
pagefile.sys : This is the actual pagefile, as the name indicates, of Windows. This file is used as virtual memory on your system.
hiberfil.sys : As the name indicates this is the file used for Hibernation. While hibernating the system stores all the content of the RAM to this file and shuts down. The next time you start your system the RAM contents are restored from this file.

For easy searching hidden or system files/folders I recommend using wList, get it from:
http://www.sharktime.com/us_wList.html
Go options and setup Search Range: Hidden and System.