useless -
having no beneficial use or incapable of functioning usefully; "a kitchen full of useless gadgets"; "she is useless in an emergency"
utile,
useful being of use or service; "the girl felt motherly and useful"; "a useful job"; "a useful member of society"
uneffective,
ineffective,
ineffectual lacking the ability or skill to perform effectively; inadequate; "an ineffective administration"; "inefficient workers"
unprofitable producing little or no profit or gain; "deposits abandoned by mining companies as unprofitable"
unserviceable not ready for service; "unserviceable equipment may be replaced"
usefulness,
utility the service (electric power or water or transportation) provided by a public utility; "the cost of utilities never decreases"; "all the utilities were lost after the hurricane"
unavailing,
futile,
ineffectual,
otiose producing no result or effect; "a futile effort"; "the therapy was ineffectual"; "an otiose undertaking"; "an unavailing attempt"