Outlook Query Builder uses Windows Desktop Search (WDS), which is a component of the Windows operating system rather than of Outlook or Exchange Server.
WDS is enabled by default on Windows PC operating systems but it is disabled by default on Windows Server operating systems.
This is because WDS has potential to use a lot of memory and disk space, which will have a detrimental effect on the performance of the host machine.
On a single-user PC this effect can be acceptable to the individual user and, if it isn’t acceptable, the user can disable WDS at will.
On a multi-user server environment, the detrimental effect can be severe and will affect the experience of all users. Such a problem would be likely to occur frequently and could be fixed only when all users are logged off and the server rebooted.
Therefore, to ensure the best experience for all our customers, on our Desktop platform WDS remains disabled and Outlook Query Builder cannot be used.
Instead you can use the Advanced Find facility. From the Outlook menu, select Tools > Instant Search > Advanced Find or press Ctrl-Shift-F, then build your search in the Advanced Find form.