PHP on IIS - access denied error

I get an access denied error while executing any PHP file. I'm running php on windows and IIS 7. It doesn't seem to be a iis error because it just show a blank page con开发者_如何转开发taining the error.

What may cause this problem?

---

Please check if the php files are encrypted. If so, please go into Properties > Advanced and uncheck Encrypt content to secure data and try running them again.