The HcScriptFileExtensions indicates which file name extensions are supported by the compression scheme. The output from dynamic files with the file extensions specified in this property are compressed by IIS.
Setting this parameter to an empty string can have an adverse effect on your server’s performance.
If this parameter is empty, all dynamic responses are sent compressed. In addition, any static file type not specified in HcFileExtensions is dynamically compressed and therefore, not cached.
Also, HcDoDynamicCompression must be set to true for dynamic compression to be performed.
The World Wide Web Publishing Service (WWW service) must be restarted before any changes to this property take effect.
Client: Requires Windows XP Professional, Windows 2000 Professional, or Windows NT Workstation 4.0.
Server: Requires Windows Server 2003, Windows 2000 Server, or Windows NT Server 4.0.