Windows Management Instrumentation filter (n)~ A query that is based on Windows Management Instrumentation (WMI) and used to filter the effect of a Group Policy object (GPO). WMI filters are written in WMI Query Language (WQL) and are evaluated on the target computer or user. If the filter evaluates to true then the GPO is applied. Otherwise the GPO is not applied. WMI filters are useful for exception management.