All the info here was very helpful, though adding IIS_USERS to c:\inetpub\ with Modify, did not solve my issue.
I had to explicityly grant Modify permission to user IUSR. I’m not enough of Windows guru to know why granted the group was not sufficient – I’m a bit hazy on Windows 2008 RC2.
One way to find which users is being used to write files, is to look at permissions of files in c:\windows\temp, (only if you have access to box).
I run on a VPS and have full admin access.
Also, use a php script <? phpinfo(); ?> to get a dump of your PHP setup, it will show you the location of temp directory (if not c:\windows\temp).
Pat.
