As a note, most computers actually come with a word processor by default. You may want to check to see if you already have one. Look for Microsoft Word, Microsoft Works, or TextEdit, depending on your OS. Alternatively, if you use the online spell checker I gave you, you can bundle it with Notepad or Wordpad, which are necessities on Windows computers and are, therefore, on all of them. (I'm pretty sure variations are also on every Mac as well.) Either that, or go get permission to install OpenOffice. If you're worried that you'll get turned down, it's practically a necessity when it comes to school papers anyway, so you're going to eventually need a word processor either way. In terms of fanfiction, it's also a necessity because the ability to save your work without publishing it is really an essential for any aspiring writer. You don't, after all, have J.K. Rowling publishing chapters of books that she wrote earlier in that same sitting.
Point is, no, you can't write directly on a board and expect us to react positively to it. =/ That's why you're getting negative feedback here. And to tell you the truth, I really don't know about where else you've posted your work, but remember that PC isn't any of those other venues. You're going to get a different sort of venue, and I really have no doubt PC's a bit stricter than what you're probably used to.
Additionally, if you think I'm repeating myself, it's only because this is a pretty important point, as pointless as you think it might be.