This problem has been talked about extensively around the forums, but no one is being clear on how to fix it. The issue first appeared after installing new Windows 2012 R2 Release. Whilst using the Windows Web platform installer 5.0 to install the framework PHP 5.6.0 and, I might add, when we tested on PHP 5.5 .11, a simple test page return the error: C:\Program Files (x86)\PHP\v5.6\php-cgi.exe – The FastCGI process exited unexpectedly
You need to install the: Visual C++ Redistributable for Visual Studio 2012 Update 4 32-bit version. and it should be noted that even if your operating system is a 64-bit operating system, you must install the 32-bit version as PHP does not run in 64 bit.
A download link is here: http://www.microsoft.com/en-us/download/details.aspx?id=30679
TIP 2: all of that has been tested and works on Windows Server 2008 R2 and Windows Server 2012 R2