Can't Import IIS logs (5 replies)

I have just installed Piwik on Windows Server 2012 and this is my first attempt to import logs into Piwik. Here is what I typed on the command line:

E:\Piwik\piwik\misc\log-analytics>python import_logs.py --url=http://arf E:\logf
iles2\Intranet\ARF_net_iis05\W3SVC769991110\ex140118.log
Fatal error: Unauthorized

The "Everyone" group has full control for the logfiles2 directory.