PHP:The FastCGI process exited unexpectedly

HTTP Error 500.0 - Internal Server Error
C:\Program Files (x86)\PHP\v5.5\php-cgi.exe - The FastCGI process exited unexpectedly

Detailed Error Information:
Module    FastCgiModule
Notification    ExecuteRequestHandler
Handler    PHP55_via_FastCGI1
Error Code    0x000000ff
Requested URL    http://localhost:80/magento/index.php/install
Physical Path    C:\inetpub\wwwroot\magento\index.php\install
Logon Method    Anonymous
Logon User    Anonymous

环境：WindowsServer2012R2

解决：

1，PHP 5.5.x/5.6.x

VC++11 runtime is installed: http://www.microsoft.com/en-us/download/details.aspx?id=30679

安装vcredist_x86.exe, windows 环境下PHP还没有64位.

PHP 5.4.x

VC++9 runtime:http://www.microsoft.com/en-us/download/details.aspx?id=5582

2，配置php.ini

extension_dir="C:\Program Files (x86)\PHP\v5.5\ext"

3，多个PHP版本

Enable FastCGI Support in IIS
Configure FastCGI recycling settings by using IIS Manager

https://www.iis.net/learn/application-frameworks/install-and-configure-php-applications-on-iis/using-fastcgi-to-host-php-applications-on-iis