It is proved that C(K) has no equivalent uniformly Gateaux differentia
ble norm (UGD) when K is an uncountable separable scattered compact sp
ace. This result is applied to obtain an example of scattered compact
K such that K-m = null set and C(K) has no UGD renorming. In the last
few years lots of remarkable results concerning renormings of C(K), wh
en K is a scattered compact have been obtained. These results are pres
ented in [DGZ, Chapter VIII and [H]. We will only mention that it foll
ows from results of Deville [D] and Haydon-Rogers [HR] that if K is sc
attered compact and K-(omega 1)= null set then C(K) admits an equivale
nt locally uniformly rotund norm whose dual norm is locally uniformly
rotund. The aim of this paper is to characterize the separable scatter
ed compact spaces K for which C(K) has an equivalent uniformly Gateaux
differentiable (UGD for short) norm.