The page cannot be found

I have seen this issue on the forums, but none of the solutions I found resolved my problem.

I have downloaded and uploaded the latest version of WordPress into the root directory of my domain on the FTP. At first it was working properly, but after some changes in themes and settings, when I go to preview my site and when I go directly to the URL (www.livewellmkt.com), the browser tells me the page cannot be found.

Thinking it was a theme issue, I activated the default theme. Still not working.

Then I figured I may have done something to mess up a file so I completely uninstalled WordPress from my server and reinstalled it (fixing the config file and all) and low and behold, nothing has changed.

Please help!