PHP not working

[aec.connex76]

Hi, I tried setting up elgg on my free hosting account. During installation, the database got installed. However, after that, during the setup, the PHP simply stopped working. It shows 500 Internal Server Error.

I even tried removing elgg and installed a simple PHP file that worked earlier. Now, even this doesn't work and give the same 500 error. Kindly help

http://aeccox.elementfx.com/
It currently has a simple PHP form. Still won't work

[descalzo]

1. All .php files have to have permissions set to 0644

2. Some settings in .htaccess can cause 500 errors. Installing some software will change .htaccess and cause problems.