  In this paper, first we study surjective isometries (not necessarily linear)
between completely regular subspaces $A$ and $B$ of $C_0(X,E)$ and $C_0(Y,F)$
where $X$ and $Y$ are locally compact Hausdorff spaces and $E$ and $F$ are
normed spaces, not assumed to be neither strictly convex nor complete. We show
that for a class of normed spaces $F$ satisfying a new defined property related
to their $T$-sets, such an isometry is a (generalized) weighted composition
operator up to a translation. Then we apply the result to study surjective
isometries between $A$ and $B$ whenever $A$ and $B$ are equipped with certain
norms rather than the supremum norm. Our results unify and generalize some
recent results in this context.
