file security/authentication

OK, I thought I had tackled this before a while a ago but forgot what I
did...

I am running IIS6 on a W2K3 server. for most of my site I have Anonymous
access authorized. I have one file that I want to use the local system ACLs
to authenticate with... I have turned off Anonymous access, I have
Integrated Authentication turned on. I have removed IUSR_XXXX from the local
ACL's. If I use my IE to access the file, the audit log shows a failure for
IUSR vice the actual user....

This is on an internal INTRANET,

How can I tweak the system so that the actual user's credintials are used to
verify file permissions.

Thansk
Carl


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