System Type: 64-bit
Windows Edition: Windows Server 2008 R2 Enterprise
Microsoft Windows Server: 6.1
Current PHP: v5.2
Upgrading to: v7.0
IIS Version: 7.5.7600.16385

For some reason I don't think this should be hard but I just can't seem to figure it out after hours of reading blog posts and things.

I am trying to update PHP for my WordPress multi-site installation on a Windows server using IIS.

• I downloaded the recommended PHP zip file.
• I put it in the Program files (86x) dir.
• I got the proper handler mapping pointing to the php-chi.exe file (named PHP_via_FastCGI, if that matters)
• Made the configuration file in PHP manager is point to the php.ini file in the same php v7.0 folder.
• And changed the environmental variables to point to the new PHP folder.

Now, the problem I'm getting is that when I go to the actual site (in Chrome), it reads...

This page isn't working 
dev.fcps.net is currently unable to handle this request.
HTTP Error 500

I am a System's Analyst at a school district that manages this install for about 300-something teachers who have WordPress pages (did I mention that it was a multi-site install?) This is the DEV server that I'm working on. The original server is down to a slow crawl all of a sudden and I'm hoping this (really really past due) upgrade will help fix some kinks.

Any ideas as to why this still isn't working? Your help and assistance is much appreciated. This is giving me a headache.