Elgg will not run


I think what is preventing the site from working is the .htaccess. I had to delete it, in order to install Elgg. After installing, it now gives an error message whether .htaccess is in there or not. If .htaccess is deleted, it gives a 400 error; if .htaccess is there, it gives an "Application error An error occurred in the website and your page could not be displayed. If you are the website owner, check your logs for details." message.

Does anyone know why this is happening?