Due to PHP server configuration, compiled as CGI, certain rules should be followed like all folders should NOT be writable and have a php.ini file in the folder where php scripts are called.
The most common issue is the writable folder, i.e. permission set to 777. The whole site may turn to Internal Server Error if you do so.
Absence of php.ini file in the folders where the PHP scripts are called will also cause internal server error. So, you need to put a php.ini file in those folders.
Where do I get the php.ini file? If what is needed are just few command lines for your site to work like register globals, safe mode on/off, etc., you can just create one (php.ini) using a notepad or text edit.
You may also request us to make a copy of the php.ini file from the server.
