Tech note FS1427
How do I configure FlashStats to read log files on a UNC network drive? [Windows]
(This discussion only applies to Windows-based systems.)
FlashStats can read data from a remote network drive. However, you may make sure that FlashStats has sufficient rights to read the log files and create a new .FLS file in the log files directory.
Windows maps network drives to drive letters. But drive letters mapped are on a per-account basis. So if you log in as Administrator and map drive N to a remote path such as \\host\path, then the Administrator user can refer to drive N. However, drive N is only defined for the Administrator user. The IIS web server runs as a different user, usually named IUSR_hostname. The IUSR_hostname user does not have a drive N mapping.
So, in order for FlashStats to be able to read and create remote log files, you must specify the remote directory name with a UNC specification, such as \\host\path, and make sure that the IUSR_hostname has Change permission on the logs directory.
You must also set the correct permissions on the remote share. For example, if you are running FlashStats on NTServer1, connecting to log files at \\NT2\C\WinNT\System32\LogFiles\in*.log, then you must edit the permissions on the C share (not the C$ share) on the machine NT2 so that the IUSR_hostname user has Change permissions. You can set the share permissions by right-clicking on the share, choosing Properties, and choosing the Sharing tab.
Incidentally, this is the same requirement that IIS has for serving web pages stored on a network drive.