Installation help – nothing displays!

Hi, I’m Amber – I’m sorry if this question has already been asked, I searched for it but couldn’t find the answer to my question.

Here’s my problem. I’ve installed wordpress before and got it work fine, and I decided to install another wp blog as my main page (the other one was a seperate weblog). I installed the new wordpress into my root directory, which already had a bunch in it – including index.html and index.php. I deleted both of those, but I’m having a big problem:

Nothing will display, at all! I just get a 404. I have a few posts, and categories, and I’m just using the default template at the moment to get everything working how I want it to (I’m going to use it as a CMS), but it’s.. nothing. I know this didn’t happen the first time I installed it.

How can I fix this? I’m using the same database for both; could that be the problem?

My new wordpress (the one I’m having problems with) is at http://www.slow-down.org. The old one, the successful one, is at http://www.slow-down.org/twitchy/.

(I put up a filler index.html page to keep people from being able to view all my files, so that’s what you see. The problem still occurs if I delete that file.)