How to Solve unexpectedly Error 500 (Timeout) PHP + FastCGI + IIS 7 (Windows 7/8/10/2008/2012 server)
I could found some links that could help you. The problem is the activityTimeout of your cgi module.
For my, works in summary this.
Open the dos console “cmd” and go to
c:\windows\system32\inetsrv\ then, execute this command, changing the path of your
appcmd set config -section:system.webServer/fastCgi "-[fullPath='C:\php\php-cgi.exe'].activityTimeout:3600"