Bruce wrote...
Harlin,
....

First, if you can't bother to spell names correctly, don't bother
including salutations.

I want the row-wise sum of CW2:CH300 if the corresponding row-wise
sum of
CT2:CW2 = 0.

You showed CW2:DH300 before, not CH2:CW300. I'll assume the original
was correct. I screwed up my second range reference. Try

=SUMPRODUCT(--(MMULT(CT2:CW300,{1;1;1;1})=0),
MMULT(CW2:DH300,{1;1;1;1;1;1;1;1;1;1;1;1}))

If you actually do want to sum CH:CW, then use

=SUMPRODUCT(--(MMULT(CT2:CW300,{1;1;1;1})=0),
MMULT(CH2:CW300,{1;1;1;1;1;1;1;1;1;1;1;1;1;1;1;1}) )