NT 4, IIS 3, and PHP 3

Hi, I'm trying to get php3 running on an NT server with IIS 3. I installed php as per the instructions, and it all appeared to work fine, except for a few functions. For instance: Basically anything having to do with file manipulation doesn't work. Like a simple counter script that works fine on my 98 and ME boxes do not work at all on the NT box and return errors such as "input/output error" or "access denied", but usually that first one. And like I said, all the scripts work fine on my 98 and ME machines running apache. Also, Authentication doesn't work. Any help is appreciated. Rick