Steps to hide text in a Notepad
Open your command prompt Start–>Run type cmd
Move to any destination for example let us assume C:\> drive
Type the below code in your command prompt
C:\>notepad filename.txt:hidden
Write some data and save the file.
Move to C:\> and open filename.txt you cannot see no data in the file.
To retrieve the hidden data open command prompt and type the same command.
C:\>notepad filename.txt:hidden
Notepad will open filename.txt file with hidden data