Why do Notepad files get all jumbeld up without line breaks?

Most times that I open a text file in notepad it keeps it's original structure. But every now and then something happens and every file I open is just one big mess of text. No line breaks.

I'm positive that this is a setting on my computer but I've never been able to figure out why it does that.



Anyone know what I'm talking about and what the fix is?