Saving a password in a .txt file

Question

Hello, so im kind of new to the whole C# language so don't flame me :P

So.. the program that I'd like to make is a program that first writes from the first textbox into a text file (ex. "hello.txt"). This i've succeded in doing.

after this I'd like the program to open the file and copy the text written inside of "hello.txt", then saving text inside "hello.txt" in a new variable. 

Then write this variable out into another textbox!

So, to make it abit clearer.

I want a form with 2 buttons and 2 textboxes,

I write whatever in the first textbox and presses the first button, the text in textbox1 will be saved inside a new text file ("hello.txt").

When this is done I wanna be able to press the second button so the text that is written inside of "hello.txt" will be shown.

I know this probably is pretty simple but I fail with reading the text inside of "hello.txt" and then writing that into  textbox2.

This is a part of my very basic login system, I want to be able to save the password in a .txt file just so you don't have to change the password everytime you start up the app.

And no, I do not want to encode the password, I simply want it as I've written above!!

Thanks in advance and sorry for my poor english..!