IIS configuration problem. Need to remove HTTP Expires header, but not possible.

IIS configuration problem. Need to remove HTTP Expires header, but not possible. Tried to use URL replace to remove the header, but this adds extra value, instead of replacing. Windows Server 2008 R2 IIS probably version 7.5 Because of this problem PHP pages are not refreshing without F5. Here is an example of problem [login to view URL] If you click link, number not increases. If you press F5 to refresh browser, number increases. Pages are beeing cached because of Expires header. I need someone to remove or fix Expires header for website.