"0" Blank File, and Clock AVI File
For Windows XP, If you look in your "My Computer\C:\WINDOWS\" In this folder, after all other folders, you find a text file named "0". If you open it, nothing will be in there, hence the filename "0". Another thing would be a file called "Clock". It's an AVI file. It can open it in Windows Media Player. It's a very simple and plain animation.

These 2 files, were probably left in by the Microsoft Programmers as Easter-Eggs for anyone that could find them.

Con Folder
1. In any windows or dos try to make a folder named 'con'.
2. You will be presented by an error that it already exists, or other error preventing you creating this directory.

"Quotes" in windows XP
Ok, there is a secret file in Windows XP called "quotes". In order to get there you must be somewhat familiar with how to use Windows, simply open up My Computer (explorer) and double click on your main drive (probably C:) next navigate to: C:\WINDOWS\SYSTEM32\DRIVERS\etc This is where the quotes file is. Open the file named quotes in your favorite text editor (notepad, MS Word) then look at the quotes put there by the MS developers!

Easier way to force win in Solitaire
Here is how to make you instantly win a game of solitaire. Simply press Alt + Shift + 2.