Easter Eggs to windows

1. Naming & Renaming Folders

For the first one, try to create a folder named CON and you will see the following thing happening:

The same thing happens when you try any of the following names:
PRN, LPT1, LPT2, (…), LPT9, NUL, COM1, (…), COM9, and CLOCK$
All of the above names are reserved device names, which cannot be used as file names or folder names, regardless of the file extension. This is a relic from DOS, which has made its way through all versions of Windows, including Windows 7.
Source: Wikipedia

2. Advanced Calculations

Let’s do some basic maths together. Please use your head first. Highlight the next two lines to see the respective answers.
What is the square root of four? It’s two, isn’t it?
And what do you get if you subtract two from two? Zero, right?
Now let’s do the above calculation using the Windows calculator. Type in 4, take the square root and from the result subtract 2. What do you get now?

See why they don’t want you to use calculators at school?
To my knowledge, there is no explanation for this result. The operation returns different numbers in different versions of Windows, so it’s possibly a bug by design or an Easter Egg and not some weird functional error. What was your result?

3. Notepad Bug (XP Only)

This bug no longer works in Windows Vista or Windows 7, but if you’re still running Windows XP, give it a try.
Launch Notepad and type the following sentence: Bush hid the facts
Now save the file as anything you like, close it and open it again. What do you see?

If you did this in Windows XP, you probably see some weird unicode characters or Chinese characters like in the screenshot above. By the way, I have to admit that I ‘forged’ the screenshot because I no longer run Windows XP.
The explanation for this bug lies in the Windows function ‘IsTextUnicode’. When a text file is encoded in Windows-1252 it is interpreted as UTF-16LE, resulting in the so-called mojibake. It means that Notepad recognizes unicode characters representing Chinese characters and translates them back into Chinese characters.
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