When I read about this, I thought it was a hoax, but:
- Create a new file in Windows Notepad.
- Type in:
this app can break - Save the file, close Notepad.
- Reopen the file to receive gibberish.
I believe this works in all versions of Windows, up to and including Windows XP. More on the Notepad bug on Wikipedia. The problem was finally fixed in Windows Vista.