I have IIS7.5 with ASPNET 4.0 running in a Parallels virtual machine on Windows 7 on an external harddisk which I connect to my MacBook Air. My website source files are on my MacBook Air. I want to configure a website within IIS7.5 that points to the files on the MacBook Air. I now have this under physical path ('Basic Settings...' in IIS): \psf\home\dropbox\inetpub\mysite My username and password for Windows 7 and OSX are the same. But when I enter those credentials under 'Connect as', it does not work when I click 'test settings'. Authentication is checked, but Authorization failed with "Path might not exist and could not be verified (\psf\home\dropbox\inetpub\mysite)". When I enter the UNC path in Windows Explorer directly I'm able to view the files. How can I configure this correctly?