Go to Command prompt, now go to the path where you want to store your secret file
Ex: c:\my secret>
Now type "notepad filename.txt"
Ex: c:\my secret>notepad sam.txt
after pressing enter notepad pops up click on yes and write any data in it
that to be viewed by public
You have created a normal text file and filled with some data
Now the real part come..
to create a secret file type "notepad filename.txt:secret.txt"
Ex: c:\my secret>notepad filename.txt:secret.txt
again a notepad pops up click on yes and write the secret data in it and save it
thats it you have created your secret file