VMWare, setting memory reservation

I am running ESXi 5.5

My VM is powered down

I rt click on the VM, goto Edit Settings, hit Resources->memory

Now I want to change the memory reservation to 0, but all the options are greyed out, even though the VM is powered down.  The reservation is set to 32 MB, but I do not seem to be able to change it because it is greyed out.

How can I change my memory reservation ?

Thanks