Sadly you hit my knowledge cap as I know nothing about running PHP on IIS.
If I have sometime over the next few days I might try to get it setup to test but no promises.
For now, you might want to see if you can run any php at all. (Just create a basic "Hello World" page or something similar.
If that runs correctly try running phpinfo() and see what it returns.
If no luck with either of those everything points to a problem with the php parsing.
Just a quick note, make sure you are running the same version of PHP as you did with WAMP.
PHP is known to make a lot of changes between version that can potentially break an entire site.