500 internal server error

[beisan-net]

500 Internal Server Error .Always I see that message when I try to open my install.php
the error message is:

Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator, webmaster@beisan.exofire.net and inform them of the time the error occurred, and anything you might have done that may have caused the error.
More information about this error may be available in the server error log.
Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.
Apache/2.2.6 (Unix) mod_ssl/2.2.6 OpenSSL/0.9.8b mod_auth_passthrough/2.1 mod_bwlimited/1.4 FrontPage/5.0.2.2635 Server at beisan.exofire.net Port 80

then I requestaed the intemidiate config for php but the prob stilllllllllllllllllllllllllllllllllllllllllllllll lllllllllllllllllllllll.
Please help:happysad::happysad::happysad:
Edit:
Note that when I used the search feature I found more than 5 or 6 cases just like mine .I think that the problem is the new php configurations feature.
It is causing many problems.
Oh yeah ,and when I try to access the install.php file from my webdisk the browser edits it.

[Corey]

500 Error is normally due to permissions being wrong. Check your permissions or post a link to where the problem is here.

-Corey

[beisan-net]

the link of the file is:
http://beisan.exofire.net/forum/install/install.php
but, what permissions do you mean?

[Fedlerner]

He means folder & files permissions.
All folders should have CHMOD 755, and files should have 644 (config files may need 666).
You can check & change this by FTP or cPanel FileManager.