Anyone of you have an idea to create fixlet to delete the unknown users? I need to create the fixlet to remove these all unknown users from managed servers.
Are the users local to the servers or part of an LDAP domain ?
In the first case you can use the relevance names of users to list all users which are local to the machine.
In the latter case you can use the relevance names of domain users to list all users which are part of the domain ( if the computer is part of a domain ).
Even if the unknown user are shown in the list then you need to remove the registry key associated with them or revoke the SID of the user from the ACL:
Yes, it should be members of LDAP domain, but I cannot ensure since there were no details information.