PHP on XP SP2 IIS Security?

Hi all a while ago I bought a new computer and set it up to run PHP on IIS using MySQL db. I did all the usual setup step as I used to for the last 5 yrs. The first problem was with image uploading. The move_uploaded_file() was not working but only if the path was in the Inetpub directory. If I wanted to upload an image on the c: drive it was fine. I use Win XP Proffesional and I'm not on a network, so I don't get the security tab on the folder properties. I decided to make the user IUSR_computername an Administrator (stupid I know, but it worked). So now I'm trying to do an fopen($filename, "w+") but it fails. If the file is outside the Inetpub directory, it works!!! Can anyone help PLEASE!!!! Thanks in advance Mario