How to remove Unregistered Users

[EFCC]

Is there a way to remove Unregistered User's information from "All Users People"  I have 3 deleted users but they are still showing under "All Users People" Can you please help me out.

EFCC Theological Forum

[EFCC]

in a previous post an administrator talks about clearing the cache on the server that hosts my forum - any comments? can somebody please do the necessary ?

Thanks

David