password protected folder in IIS for clickonce deployment

Question

Hey,
Im not sure this is the correct forum for this but it seemed possibly the most appropriate.  I have an application that i have published (for ClickOnce deployment) to a folder on my web server.  Now it all worked fine, but ever since i changed the permissions in IIS to not allow anonymous access to this folder, i now receive an error when trying to run the setup file.
"URLDownloadToCacheFile failed with HRESULT '-2146697191'"
It is essentially saying it is unable to download.  Now im fairly sure this is caused by me removing anonymous access but i do not know how to fix it !  I cannot allow anonymous access.
Any pointers would be great!
regards,