HTTP Error 500.0 - Internal Server Error An unknown FastCGI error occured

Question

I'm running IIS7 on Windows Server 2008 with Plesk 10. I have website under plesk and a site not under plesk and only on IIS. The website under plesk successfully runs php files but the other website gives error:

HTTP Error 500.0 - Internal Server
Error An unknown FastCGI error occured

Module FastCgiModule
Notification ExecuteRequestHandler
Handler PHP5-FastCGI-php
Error Code 0x8007010b
Requested URL http://*.com:80/test.php Physical
Path C:\IIS*.com\test.php
Logon Method Anonymous
Logon User Anonymous

PHP5-FastCGI-php is configured exactly like the site under plesk. php-cgi.exe is located at C:\Program Files (x86)\Parallels\Plesk\Additional\PleskPHP5\

EDIT: Here is my php.ini but I don't get any errors.

error_reporting = E_ALL & ~E_NOTICE
display_errors = On
display_startup_errors = Off
log_errors = On
error_log = "C:\Program Files (x86)\...\log\test.log"
error_log = syslog

Answer 1

Granted Read & execute, List folder contents for Everyone on folder

C:\Program Files (x86)\Parallels\Plesk\Additional\PleskPHP5

and now php is up and running for every Application Pool. The main problem with plesk was, only sites running with Application Pool Identity of a user which is member of psacln.

Answer 2

Preface: This solution worked for my Python Flask application

If your file permissions are correct, the problem might lie in your Application Pools settings.

1. Go to IIS manager
2. Click on your server's Application Pools tab
3. Click Set Application Pool Defaults...
4. Set the Identity under Process Model to LocalSystem

Future readers, I spent several days searching for a solution to this problem. Hopefully this fixes your problem in a fraction of the time :)