I have a mac and followed the instructions using the plain text and matched the required preferences etc (step 107-112). I used the HTML - https://webto.salesforce.com/servlet/servlet.WebToLead?encoding=UTF-8" method="POST and followed the rest exactly. However on step 130 when I click the the file I created on my desktop I do not get the same outcome shown in the picture on the instructions and instead get this HTML. I don't know how to fix this and can't proceed without it.

thank you!! finally finished that lab! - my mistake was not copying the entire thing
so i redid the steps 89-98 then skipped to 104 and im having the exact same problem when click the file i created (step 130). Not sure what the issue is. Also want to verify that <form action="https://webto.salesforce.com/servlet/servlet.WebToLead?encoding=UTF-8" method="POST"> is exactly what i am suppose to be copying and pasting to text edit.
what html am i suppose to use?
Yeah, I can see that your problem is not with TextEdit. That part's fine. But you missed Step 104 where you were supposed to copy all the HTML you had generated - the stuff in the screencap below 104.
It's easy to fix, tho. Just redo Steps 89-98 and then skip to 104 and go from there and you'll be fine!