Does ZipEnable work with SharePoint Portal Server?
Yes, compression can be configured for SharePoint Portal Server using ZipEnable (and IIS 6.0 native compression in the core Web server). If you install ZipEnable on a server running SharePoint Portal Server and encounter an error, you should verify that the “check if file exists” option is deselected for the ZEIsapi.dll wildcard extension for your virtual directories. This can be done through Internet Services Manager >> Web Sites folder >> Properties >> Home Directory (or Virtual Directory) tab >> click Configuration In the Add/Edit Application Extension Mapping dialog, deselect the “Verify that file exists” checkbox.