I thought I would add this as a possible solution since after I found this thread I had to search for another hour or so to find what worked for me.
So I just like SonnyRay did all of the steps, but it still didn't work.
What I found is that the problem is if you're on a 64 bit machine you have to set up IIS7 to Enable 32-bit applications.
To do this, in the Internet Information Services Manager:
1) select "Application Pools" (Mine is located in the left file menu of the screen.
2) Then in the middle of the screen Right click on your application pool and select Advanced Settings
3) Then in the Advanced Settings window towards the top where it says "Enable 32-Bit Applications" change it to True.
4) Click OK and then restart the server.
You should now be able to see the php information page (phpinfo.php)
assuming that you have the phpinfo.php file saved into c:\inetpub\wwwroot
I hope this helps anyone else that runs into this problem.