IIS_IUSRS permission

Hi guys:

In our project we are using an app upload images(.png) into a server and read and display them on a webpage(published in IIS 6.1).

Each time an image uploaded, in the security tab of the uploaded image file 's property, the IIS_IUSRS account does not have any permission , which will give a 401 error page and prevent the web site to read and display the image . If I manually give the IIS_IUSRS full control, then it works.

I am wondering why this is happening. Is there any way to automatically give the new uploaded image file full control permission for IIS_IUSRS?

thank you very much for any respond1